UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549
                                    FORM 10-K
                (X) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                   FOR THE FISCAL YEAR ENDED DECEMBER 31, 2002
                                       OR
              ( ) Transition report pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934
                       For the transition period from to .

                         COMMISSION FILE NUMBER 1-14756

                               AMEREN CORPORATION
             (Exact name of registrant as specified in its charter)

         Missouri                                     43-1723446
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
incorporation or organization)

                 1901 Chouteau Avenue, St. Louis, Missouri 63103
              (Address of principal executive offices and Zip Code)

       Registrant's telephone number, including area code: (314) 621-3222

           Securities Registered Pursuant to Section 12(b) of the Act:

Title of each class                    Name of each exchange on which registered
-------------------                    -----------------------------------------
Common Stock, $ .01 par value and               New York Stock Exchange
 Preferred Share Purchase Rights
Normal Units                                    New York Stock Exchange

        Securities Registered Pursuant to Section 12(g) of the Act: None.

     Indicate  by check mark  whether the  registrant  (1) has filed all reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days. Yes (X). No ( ).

     Indicate by check mark if disclosure of delinquent  filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's  knowledge,  in definitive proxy or information  statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. ( ).

     Indicate by check mark whether the registrant is an  accelerated  filer (as
defined in Rule 12b-2 of the Securities Exchange Act of 1934). Yes (X). No ( ).

     As of June 28, 2002, the registrant had 144,774,189  shares of its $.01 par
value common stock  outstanding.  The aggregate  market value of these shares of
common stock (based upon the closing price of these shares on the New York Stock
Exchange on that date) held by non-affiliates was $301,580,783.

     As of March 21, 2003, the registrant had 160,720,970 shares of its $.01 par
value common stock outstanding.

                      DOCUMENTS INCORPORATED BY REFERENCE:

     Portions of the registrant's  2002 Annual Report to Shareholders  (the 2002
Annual  Report)  are  incorporated  by  reference  into  Parts I, II and IV. The
registrant's  consolidated  financial  statements  for  the  fiscal  year  ended
December 31, 2002, including the notes thereto, and the Management's  Discussion
and  Analysis  of  Financial   Condition  and  Results  of  Operations  for  the
registrant,  contained in the portions of the 2002 Annual Report incorporated by
reference  herein were also filed with the  Commission by the  registrant on its
Current Report on Form 8-K dated March 5, 2003.

     Portions of the registrant's definitive proxy statement for the 2003 annual
meeting of shareholders are incorporated by reference into Part III.



                                TABLE OF CONTENTS

PART I                                                                      Page
                                                                            ----
Item  1   Business
          General........................................................      1
          Capital Program and Financing..................................      2
          Rates and Regulation...........................................      4
          Fuel Supply for Electric Generating Facilities.................      5
          Industry Issues................................................      7
          Operating Statistics...........................................      7
          Available Information..........................................      7
Item  2   Properties.....................................................      7
Item  3   Legal Proceedings..............................................     11
Item  4   Submission of Matters to a Vote of Security Holders............     13

Executive Officers of the Registrant (Item 401(b) of Regulation S-K).....     13

PART II

Item  5   Market for Registrant's Common Equity and Related
                 Shareholder Matters.....................................     19
Item  6   Selected Financial Data........................................     19
Item  7   Management's Discussion and Analysis of Financial Condition
                 and Results of Operations...............................     19
Item  7A  Quantitative and Qualitative Disclosures About Market Risk.....     19
Item  8   Financial Statements and Supplementary Data....................     19
Item  9   Changes in and Disagreements with Accountants on Accounting
                 and Financial Disclosure................................     19

PART III

Item 10   Directors and Executive Officers of the Registrant.............     20
Item 11   Executive Compensation.........................................     20
Item 12   Security Ownership of Certain Beneficial Owners
                 and Management..........................................     20
Item 13   Certain Relationships and Related Transactions.................     20
Item 14   Controls and Procedures........................................     20


PART IV

Item 15 Exhibits, Financial Statement Schedules and Reports on Form 8-K..     22

SIGNATURES     ..........................................................     32

CERTIFICATIONS ..........................................................     33

EXHIBIT INDEX  ..........................................................     35

     This Form 10-K contains "forward-looking"  statements within the meaning of
Section 21E of the Securities Exchange Act of 1934, as amended.  Forward-looking
statements  should be read with the cautionary  statements and important factors
included  in  this  Form  10-K  at page 12  under  the  heading  Forward-Looking
Statements.  Forward-looking statements are all statements other than statements
of historical fact, including those statements that are identified by the use of
the words "anticipates," "estimates," "expects," "intends," "plans," "predicts,"
"projects" and similar expressions.



                                     PART I

ITEM 1.  BUSINESS

GENERAL

     Ameren Corporation (Ameren) was incorporated in Missouri on August 7, 1995.
On December 31, 1997,  following the receipt of all required  approvals,  CIPSCO
Incorporated  (CIPSCO) and Union Electric  Company combined with the result that
the common  shareholders of CIPSCO and Union Electric  Company became the common
shareholders of Ameren,  and Ameren became the owner of 100% of the common stock
of Union  Electric  Company and the operating  subsidiaries  of CIPSCO:  Central
Illinois Public Service Company and CIPSCO Investment  Company. We completed our
acquisition  of CILCORP  Inc.  (CILCORP)  on January  31, 2003 and of AES Medina
Valley Cogen (No. 4) LLC on February 4, 2003 from The AES Corporation (AES). See
CILCORP Acquisition below for further information.

     When we  refer  to  Ameren,  our,  we or us,  we are  referring  to  Ameren
Corporation on a consolidated basis. In certain circumstances,  our subsidiaries
are  specifically  referenced  in order to  distinguish  among  their  different
business activities.

     Ameren is a public utility holding  company  registered with the Securities
and Exchange  Commission  (SEC) under the Public Utility  Holding Company Act of
1935 (PUHCA),  as amended,  and does not own or operate any  significant  assets
other than the stock of its subsidiaries.  Ameren is headquartered in St. Louis,
Missouri.  Dividends on Ameren's common stock are dependent on  distributions to
be made to it by its subsidiaries. Our primary subsidiaries are as follows:

o    Union  Electric   Company,   which  operates  a   rate-regulated   electric
     generation,  transmission and distribution  business,  and a rate-regulated
     natural gas  distribution  business in Missouri  and  Illinois as AmerenUE.
     AmerenUE was  incorporated in Missouri in 1922 and is successor to a number
     of companies,  the oldest of which was organized in 1881. It is the largest
     electric  utility in the State of Missouri  and  supplies  electric and gas
     service in parts of central and eastern  Missouri and west central Illinois
     having  an  estimated   population  of  2.6  million   within  an  area  of
     approximately  24,500 square  miles,  including the greater St. Louis area.
     AmerenUE  supplies  electric service to approximately 1.2 million customers
     and natural gas service to approximately 130,000 customers.
o    Central  Illinois Public Service  Company,  which operates a rate-regulated
     electric  and  natural  gas  transmission  and  distribution   business  in
     Illinois,  as AmerenCIPS.  AmerenCIPS was incorporated in Illinois in 1902.
     It supplies  electric  and gas  utility  service to portions of central and
     southern Illinois having an estimated  population of 820,000 within an area
     of approximately 20,000 square miles.  AmerenCIPS supplies electric service
     to approximately 325,000 customers and natural gas service to approximately
     170,000 customers.
o    Central  Illinois  Light  Company,  a  subsidiary  of CILCORP  Inc.,  which
     operates  a  rate-regulated  transmission  and  distribution  business,  an
     electric generation business, and a rate-regulated natural gas distribution
     business  in Illinois  as  AmerenCILCO.  AmerenCILCO  was  incorporated  in
     Illinois in 1913. It supplies  electric and gas utility service to portions
     of central and east central Illinois in an area of approximately  3,700 and
     4,500 square miles, respectively.  AmerenCILCO supplies electric service to
     about 200,000 customers and natural gas service to about 205,000 customers.
     See CILCORP Acquisition below for further information.
o    AmerenEnergy  Resources Company (Resources Company),  which consists of non
     rate-regulated  operations.  Subsidiaries include  AmerenEnergy  Generating
     Company  (Generating  Company)  that operates non  rate-regulated  electric
     generation  in  Missouri  and  Illinois,   AmerenEnergy  Marketing  Company
     (Marketing  Company),  which  markets  power  for  periods  over one  year,
     AmerenEnergy  Fuels and Services  Company,  which procures fuel and manages
     the related  risks for our  affiliated  companies and  AmerenEnergy  Medina
     Valley Cogen (No. 4), LLC which  indirectly  owns a 40 megawatt,  gas-fired
     electric   generation   plant.  On  February  4,  2003,  we  completed  our
     acquisition of AES Medina Valley Cogen (No. 4), LLC from AES and renamed it
     AmerenEnergy  Medina  Valley Cogen (No.  4), LLC.  See CILCORP  Acquisition
     below for  further  information.  Generating  Company was  incorporated  in
     Illinois in March 2000 in conjunction  with the Illinois  Electric  Service
     Customer  Choice  and Rate  Relief  Law of 1997 (the  Illinois  Law).  This
     Illinois Law provides for electric  utility  restructuring  and  introduces
     competition  into  the  retail  supply  of  electric  energy  in  Illinois.
     Generating  Company  commenced  operations  on May 1, 2000 when  AmerenCIPS
     transferred  to Generating  Company all of the  following:  its  generating
     assets,  consisting of the generating facilities described below under Item
     2. Properties;  all related fuel, supply,  transportation,  maintenance and
     labor  agreements;  approximately  45% of AmerenCIPS'  employees;  and some
     other related rights, assets and liabilities.

                                       1



o    AmerenEnergy,  Inc.  (AmerenEnergy)  which serves as a power  marketing and
     risk  management  agent for our affiliated  companies for  transactions  of
     primarily less than one year.
o    Electric  Energy,  Inc.  (EEI),  which  operates  electric  generation  and
     transmission  facilities in Illinois. EEI supplies electric power primarily
     to a uranium enrichment plant located in Paducah,  Kentucky.  We have a 60%
     ownership  interest  in EEI  and  consolidate  it for  financial  reporting
     purposes.
o    Ameren Services  Company (Ameren  Services),  which provides shared support
     services to us and our subsidiaries.

     For  additional  information  regarding the  acquisition of CILCORP and AES
Medina  Valley  Cogen (No.  4), LLC,  see Recent  Developments  in  Management's
Discussion  and Analysis of Financial  Condition and Results of  Operations  and
Notes 1 and 18 to our  Consolidated  Financial  Statements  of the  2002  Annual
Report pages incorporated herein by reference under Items 7 and 8.

     For the year  2002,  91.7%  (2001 - 90.9%;  2000 - 91.5%) of our  operating
revenues were derived from the sale of electric energy,  8.2% (2001 - 8.9%; 2000
- 8.4%) came from the sale of natural gas,  and 0.1% (2001 - 0.2%;  2000 - 0.1%)
came from other sources.

     We employed  7,422  employees at December 31, 2002.  For  information  on a
voluntary  retirement  program offered in December 2002 and on labor  agreements
and  other  labor  matters,  see  Note  9 and  Note  14,  respectively,  to  our
Consolidated  Financial  Statements of the 2002 Annual Report pages incorporated
herein by reference under Item 8.

CILCORP Acquisition

     On January 31,  2003,  after  receipt of the  necessary  regulatory  agency
approvals   and   clearance   from  the   Department   of   Justice   under  the
Hart-Scott-Rodino  Antitrust  Improvements  Act, we completed our acquisition of
all of the outstanding  common stock of CILCORP from AES.  CILCORP is the parent
company of Peoria, Illinois-based Central Illinois Light Company, which operated
as CILCO. With the acquisition, CILCO became an Ameren subsidiary, but remains a
separate utility company, operating as AmerenCILCO. On February 4, 2003, we also
completed  our  acquisition  of AES Medina  Valley  Cogen (No.  4), LLC  (Medina
Valley),  which indirectly owns a 40 megawatt,  gas-fired electric co-generation
plant. With the acquisition,  Medina Valley became a wholly-owned  subsidiary of
Resources Company and was renamed AmerenEnergy Medina Valley Cogen (No. 4), LLC.
The  CILCORP  and  AmerenEnergy  Medina  Valley  Cogen (No.  4),  LLC  financial
statements will be included in our consolidated  financial  statements effective
with the January and February 2003 acquisition dates.

     We acquired  CILCORP to complement our existing  Illinois  electric and gas
operations.  The purchase included CILCO's  rate-regulated  electric and natural
gas businesses in Illinois serving  approximately 200,000 and 205,000 customers,
respectively,  of which approximately  150,000 are combination  electric and gas
customers.  CILCO's  service  territory is contiguous to our service  territory.
CILCO  also  has  a non  rate-regulated  electric  and  gas  marketing  business
principally  focused in the  Chicago,  Illinois  region.  Finally,  the purchase
includes   approximately  1,200  megawatts  of  largely  coal-fired   generating
capacity, most of which is expected to become non rate-regulated in 2003.

     The total  purchase price was  approximately  $1.4 billion and included the
assumption of CILCORP and Medina  Valley debt and preferred  stock at closing of
approximately  $900  million,   with  the  balance  of  the  purchase  price  of
approximately $500 million paid with cash on hand. The purchase price is subject
to certain  adjustments  for  working  capital  and other  changes  pending  the
finalization  of CILCORP's  closing  balance  sheet.  The cash  component of the
purchase  price came from Ameren's  issuances in September  2002 of 8.05 million
common shares and in early 2003 of 6.325 million common shares.

     For  additional   information   regarding  our  business  operations,   see
Management's  Discussion  and  Analysis of  Financial  Condition  and Results of
Operations  and  Note 1 to our  Consolidated  Financial  Statements  of the 2002
Annual Report pages incorporated herein by reference under Items 7 and 8.


CAPITAL PROGRAM AND FINANCING

     For information on our capital program and financial  needs,  see Liquidity
and Capital  Resources  in  Management's  Discussion  and  Analysis of Financial
Condition and Results of Operations and Notes 5, 7, 8 and 14 to our Consolidated
Financial  Statements  of the 2002 Annual  Report pages  incorporated  herein by
reference under Items 7 and 8.

                                       2



Financing

     In August 2002, a shelf  registration  statement filed by AmerenUE with the
SEC on Form S-3 was declared effective.  This statement  authorized the offering
from time to time of up to $750 million of various  forms of long-term  debt and
trust  preferred  securities to refinance  existing debt and preferred stock and
for general  corporate  purposes,  including the  repayment of  short-term  debt
incurred to finance  construction  expenditures and other working capital needs.
On March 10, 2003, AmerenUE issued,  pursuant to the shelf registration referred
to above,  $184  million  of 5.50%  senior  secured  notes  due March 15,  2034.
AmerenUE expects to use the net proceeds of the issuance of  approximately  $180
million,  along  with  other  funds to redeem  prior to  maturity  $104  million
principal amount of outstanding 8.25% first mortgage bonds due October 15, 2022,
at a redemption  price of 103.61% of par,  plus accrued  interest,  and to repay
short-term  debt  incurred to pay at maturity  $75 million  principal  amount of
8.33% first mortgage bonds that were due in December 2002.

     To issue first mortgage bonds and preferred stock,  AmerenCIPS and AmerenUE
each must comply with earnings tests contained in their respective mortgages and
Articles of Incorporation.  For the issuance of additional first mortgage bonds,
generally,  earnings  coverage  of twice the  annual  interest  charges on first
mortgage  bonds  outstanding  and to be issued is required.  Generally,  for the
issuance of additional  preferred stock,  earnings  coverage of one and one-half
times annual  interest  charges and preferred  stock dividends is required under
the AmerenCIPS Articles of Incorporation,  and earnings coverage of at least two
and one-half times the annual dividend on preferred stock  outstanding and to be
issued is required under AmerenUE's  Articles of  Incorporation.  The ability to
issue such  securities  in the future will depend on coverages at that time.  At
December  31, 2002,  each  company had and expects to continue to have  adequate
coverage  ratios  for  anticipated  requirements.  See  Notes  6  and  8 to  our
Consolidated  Financial  Statements of the 2002 Annual Report pages incorporated
herein by reference under Item 8 for additional financing information.

     CILCORP's and AmerenCILCO's  financial agreements include customary default
or cross  default  provisions  that could impact the continued  availability  of
credit or result in the  acceleration of repayment.  Many of Ameren's  committed
credit  facilities  require the borrower to represent,  in  connection  with any
borrowing under the facility, that no material adverse change has occurred since
certain  dates.  Ameren's  financing  arrangements  do not contain credit rating
triggers with the exception of certain triggers within  AmerenCILCO's  financing
arrangements.

     An event of default  will occur under a $25 million  AmerenCILCO  committed
credit facility if AmerenCILCO  fails to maintain a Moody's rating on its senior
secured  debt above Baa2 and a Fitch  credit  rating of BBB-.  Under  agreements
governing  $4.7  million  of  AmerenCILCO  funded  bank debt,  AmerenCILCO  must
maintain a Moody's  investment  grade  rating or an event of default will occur.
Also,  under a $100 million  funded bank term loan,  AmerenCILCO  must  maintain
investment  grade  ratings  for its first  mortgage  bonds  from at least two of
Standard & Poor's, Moody's and Fitch. As of February 2003,  AmerenCILCO's senior
secured  debt  ratings  from  these  rating   agencies  were  A-,  A2  and  BBB,
respectively. AmerenCILCO's Fitch ratings are on positive credit watch.

     At its current ratings level,  covenants in CILCORP's  indenture  governing
its $475  million  senior  notes  require  CILCORP to maintain a debt to capital
ratio of no greater than 0.67 to 1.0 and an interest  coverage ratio of at least
2.2 to 1.0 in order to make any payment of  dividends or  intercompany  loans to
affiliates   other  than  its  direct  and  indirect   subsidiaries,   including
AmerenCILCO.  However,  in the event CILCORP's senior long-term debt rating from
Fitch is increased by one notch to BBB,  CILCORP may make any such  distribution
or intercompany  loan without being subject to these tests  described  above. At
December  31,  2002,  CILCORP's  debt to  capital  ratio was 0.60 to 1.0 and its
interest  coverage ratio was 2.72 to 1.0,  calculated in accordance with related
provisions in this indenture.

     The common  stock of  AmerenCILCO  is pledged as security to the holders of
CILCORP's $475 million of senior notes and bonds.

     Covenants  in  AmerenCILCO's  $100  million  bank term loan  require  it to
maintain a minimum level of common  stockholder  equity and limit  AmerenCILCO's
ability to pay  dividends or otherwise  make  distributions  with respect to its
common  stock.  Any  violation  of these  covenants  will  result in an event of
default  under this  facility.  Under the  minimum  common  equity  requirement,
AmerenCILCO  must  maintain a minimum level of common  stockholder  equity which
increases from the date the facility was entered based on ongoing earnings.  The
maintenance  of this test is determined  upon each  anniversary  of the loan. If
this test was performed as of December 31, 2002, the minimum common equity level
requirement would equal approximately $301 million. At that date,  AmerenCILCO's
common  equity,  calculated in accordance  with this provision was $329 million.
Under the

                                       3



restricted payments provision,  AmerenCILCO may only pay dividends to CILCORP up
to $45 million annually subject to limited carry forward if not fully utilized.

     For additional  discussion of indenture and credit agreement provisions and
covenants,  see Liquidity and Capital  Resources in Management's  Discussion and
Analysis of  Financial  Condition  and Results of  Operations  and Note 8 to our
Consolidated  Financial  Statements of the 2002 Annual Report pages incorporated
by reference under Items 7 and 8.


RATES AND REGULATION

Rates

     Rates that we are  allowed to charge for our  services  are the single most
important item  influencing  our financial  position,  results of operations and
liquidity.  We are  highly  regulated.  The rates we charge  our  customers  are
determined by governmental  organizations.  Decisions by these organizations are
influenced by many factors,  including our recent cost of providing service, our
quality  of  service,  regulatory  staff  knowledge  and  experience,   economic
conditions and social and political views. Decisions made by these organizations
regarding  our rates  could have a material  impact on our  financial  position,
results of operations and liquidity.

     For  the  year  2002,  approximately  60%,  25%,  and  15% of our  electric
operating  revenues were based on rates regulated by the Missouri Public Service
Commission  (MoPSC),  the  Illinois  Commerce  Commission  (ICC) and the Federal
Energy  Regulatory  Commission  (FERC),  respectively.  For  information on rate
matters in these  jurisdictions,  including  AmerenUE's recent Missouri electric
rate case,  see Results of Operations  and  Regulatory  Matters in  Management's
Discussion  and Analysis of Financial  Condition and Results of  Operations  and
Note 2 to our Consolidated  Financial Statements of the 2002 Annual Report pages
incorporated herein by reference under Items 7 and 8.

General Regulatory Matters

     As a  holding  company  registered  with the SEC under  the  PUHCA,  we are
subject to the regulatory provisions of the PUHCA, including provisions relating
to the issuance of securities,  sales and acquisitions of securities and utility
assets, affiliate transactions,  financial reporting requirements,  the services
performed by Ameren Services and AmerenEnergy  Fuels and Services  Company,  and
the  activities  of certain  other  subsidiaries.  Issuance  of  short-term  and
long-term  debt and other  securities  by Ameren and  issuance  of debt having a
maturity of twelve months or less by AmerenCIPS,  AmerenUE and  AmerenCILCO  are
subject to approval by the SEC under the PUHCA.

     Generating  Company  is  certified  by the  FERC  as an  "exempt  wholesale
generator"  under the Energy Policy Act of 1992 and as a result is not a "public
utility company" under the PUHCA. As an exempt wholesale  generator,  Generating
Company is exempt from most of the provisions of the PUHCA that otherwise  would
apply  to it as a  subsidiary  of a  registered  holding  company.  Issuance  of
securities by Generating Company is not subject to approval by the SEC under the
PUHCA.  The SEC has no  jurisdiction  over the sale of electricity by Generating
Company to  affiliates  or  non-affiliates.  The SEC may impose  limitations  on
Ameren in  connection  with its financing for the purpose of investing in exempt
wholesale  generators  and  foreign  utility  companies  if  Ameren's  aggregate
investment  in  those  activities  exceeds  50%  of  its  consolidated  retained
earnings.  At December 31, 2002, Ameren's aggregate investment in those entities
was 23.7% of its consolidated retained earnings.

     AmerenCIPS,  AmerenUE and  AmerenCILCO are subject to regulation by the ICC
and AmerenUE is also subject to  regulation  by the MoPSC as to rates,  service,
issuance of equity  securities,  issuance of debt having a maturity of more than
twelve months,  mergers,  and various other matters.  Generating  Company is not
subject to regulation by the ICC or the MoPSC.

     AmerenCIPS,  AmerenUE,  AmerenCILCO and Generating Company are also subject
to  regulation  by the FERC as to  rates  and  charges  in  connection  with the
wholesale  sale of energy and  transmission  in  interstate  commerce,  mergers,
affiliate  transactions,  and certain other matters.  Issuance of short-term and
long-term debt by Generating Company is subject to approval by the FERC.

     In  many  states,  including  Illinois,  companies  that  sell  electricity
directly to retail customers  pursuant to state statutes and regulations must be
registered  or  licensed.  Marketing  Company has obtained  "alternative  retail

                                       4



electricity  supplier" status in Illinois and plans to seek comparable status in
other states where retail competition is developing.  AmerenCILCO is an Illinois
electric  utility,  and as such,  is permitted to provide  power and energy on a
competitive basis to retail customers located outside its service territory.

     Operation of  AmerenUE's  Callaway  plant is subject to  regulation  by the
Nuclear Regulatory Commission. Its Facility Operating License expires on October
18,  2024.  AmerenUE's  Osage  hydroelectric  plant  and  AmerenUE's  Taum  Sauk
pumped-storage  hydro plant,  as licensed  projects under the Federal Power Act,
are  subject to FERC  regulations  affecting,  among other  things,  the general
operation  and  maintenance  of the  projects.  The  license for the Osage Plant
expires on February 28, 2006, and the license for the Taum Sauk Plant expires on
June 30, 2010. We are currently seeking renewal of our Osage Plant license.  Our
Keokuk Plant and dam located in the Mississippi River between Hamilton, Illinois
and Keokuk, Iowa, are operated under authority, unlimited in time, granted by an
Act of Congress in 1905.

     For information on regulatory matters in these jurisdictions, including the
current  status of electric  transmission  matters  pending before the FERC, see
Regulatory  Matters  in  Management's   Discussion  and  Analysis  of  Financial
Condition and Results of  Operations  and Note 2 to our  Consolidated  Financial
Statements  of the 2002 Annual  Report  pages  incorporated  herein by reference
under Items 7 and 8.

Environmental Matters

     Certain  of  our  operations  are  subject  to  federal,  state  and  local
environmental  regulations  relating to the safety and health of personnel,  the
public and the environment,  including the identification,  generation, storage,
handling,  transportation,  disposal, record keeping, labeling, reporting of and
emergency response in connection with hazardous and toxic materials,  safety and
health standards, and environmental protection requirements, including standards
and limitations  relating to the discharge of air and water pollutants.  Failure
to comply with those statutes or regulations could have material adverse effects
on us,  including the  imposition  of criminal or civil  liability by regulatory
agencies or civil  fines and  liability  to private  parties,  and the  required
expenditure of funds to bring us into compliance.  We believe we are in material
compliance with existing regulations.

     The U.S.  Environmental  Protection  Agency  (EPA) issued a rule in October
1998  requiring  22  Eastern  states  and the  District  of  Columbia  to reduce
emissions of NOx in order to reduce ozone in the Eastern  United  States.  Among
other things,  the EPA's rule  establishes an ozone season,  which runs from May
through September, and a NOx emission budget for each state, including Illinois.
The EPA rule requires states to implement controls  sufficient to meet their NOx
budget by May 31, 2004.  Total capital  expenditures to meet the AmerenCILCO NOx
emission requirements are estimated to be $123 million, of which $75 million was
expended  through 2002.  These costs include the  installation  of two Selective
Catalytic Reduction (SCR) units and combustion control modifications.

     For additional  discussion of environmental  matters,  including NOx credit
requirements, see Liquidity and Capital Resources in Management's Discussion and
Analysis of Financial  Condition  and Results of  Operations  and Note 14 to our
Consolidated  Financial  Statements of the 2002 Annual Report pages incorporated
by reference under Items 7 and 8.




FUEL SUPPLY FOR ELECTRIC GENERATING FACILITIES

Cost of Fuels                                                                  Year
(Per Million BTU)                           -----------------------------------------------------------------------
                                               2002            2001            2000           1999          1998
                                               ----            ----            ----           ----          ----
                                                                                       
AmerenUE
                    Coal                      91.352(cent)     98.228(cent)   96.004(cent)  100.685(cent) 100.015(cent)
                    Nuclear                   38.051(cent)     37.184(cent)   40.269(cent)   46.552(cent)  48.803(cent)
                    Natural Gas (a)          340.689(cent)    402.546(cent)  429.354(cent)  243.315(cent) 226.572(cent)
                    Average - all fuels (b)   81.325(cent)     86.696(cent)   84.213(cent)   89.833(cent)  90.378(cent)

AmerenCIPS/Generating Company (c)
                    Coal                     125.456(cent)    121.791(cent)  123.770(cent)  139.700(cent) 152.738(cent)
                    Natural Gas (a)          396.150(cent)    439.744(cent)     -              -             -
                    Average - all fuels (b)  145.220(cent)    142.120(cent)  129.169(cent)  140.615(cent)  155.045(cent)



                                       5



     (a)  The fuel cost for  natural gas  represents  the actual cost of natural
          gas and variable costs for transportation, storage, balancing and fuel
          losses for  delivery to the plant.  In  addition,  the fixed costs for
          firm   transportation  and  firm  storage  capacity  are  included  to
          calculate a  "fully-loaded"  fuel cost for the generating  facilities.
          Prior to 2001,  the use of natural gas by  AmerenCIPS  and  Generating
          Company was minimal.
     (b)  Represents all fuels utilized in our electric  generating  facilities,
          to the extent applicable,  including coal, nuclear,  natural gas, oil,
          propane, tire chips, and handling.
     (c)  On May 1, 2000, all of AmerenCIPS' electric generating  facilities and
          related fuel supply agreements were transferred to Generating  Company
          (see General section above).

Coal

     We  have a  policy  of  maintaining  coal  inventory  consistent  with  our
historical  usage. We may adjust levels based on  uncertainties of supply due to
potential work stoppages,  delays in coal deliveries,  equipment  breakdowns and
other factors.  As of December 31, 2002 and 2001,  approximately  59 days and 56
days, respectively, supply of coal was in inventory. For the year ended December
31, 2002, coal represented approximately 82% of our fuel supply.

Nuclear

     The  components of the nuclear fuel cycle  required for nuclear  generating
units are as follows:

     o    uranium;
     o    conversion of uranium into uranium hexafluoride;
     o    enrichment of uranium hexafluoride;
     o    conversion of enriched uranium  hexafluoride  into uranium dioxide and
          the fabrication into nuclear fuel assemblies; and
     o    disposal and/or reprocessing of spent nuclear fuel.

     We have  agreements  and/or  inventories  to  fulfill  AmerenUE's  Callaway
nuclear  plant  needs  for  uranium,  conversion,   enrichment  and  fabrication
services.  Such  needs  are  satisfied  through  2004,  with  the  exception  of
enrichment  services.  A supply of enrichment  services for unfilled needs after
2004 is being  pursued.  Additional  contracts  will be entered into in order to
supply  nuclear fuel during the  remainder  of the life of the plant,  at prices
which cannot now be accurately  predicted.  The Callaway plant normally requires
refueling at 18-month  intervals,  and the next  refueling is scheduled  for the
spring of 2004. The Callaway plant is out of service for approximately one month
during a refueling.

     For the year ended December 31, 2002, nuclear represented approximately 13%
of our fuel supply. See Note 15 to our Consolidated  Financial Statements of the
2002 Annual  Report  pages  incorporated  herein by  reference  under Item 8 for
additional information.

Natural Gas

     The combustion  turbine  generator  equipment  (CTs),  which we placed into
commercial  operation  in 2002,  2001 and 2000 are fueled by natural gas or have
the  capability  to use  natural  gas or oil.  We use  natural gas to supply our
generating   facilities  during  peak  generating   periods.   Our  natural  gas
procurement  strategy is designed to ensure  reliable and immediate  delivery of
natural gas by optimizing  transportation,  storage,  and balancing  options and
minimizing  cost and price risk by  structuring  various  supply  agreements  to
maintain  access to multiple gas pools and supply basins and reducing the impact
of  price  volatility.  For the  year  ended  December  31,  2002,  natural  gas
represented  approximately 2% of our fuel supply. For additional  information on
CTs  and  related  fuel  matters,   see  Liquidity  and  Capital  Resources  and
Quantitative  and  Qualitative  Disclosures  About  Market Risk in  Management's
Discussion  and Analysis of Financial  Condition and Results of  Operations  and
Note 14 to our Consolidated Financial Statements of the 2002 Annual Report pages
incorporated herein by reference under Items 7 and 8.

Oil

     The  actual  and  prospective  use of  oil is  minimal,  and  we  have  not
experienced  and do not expect to experience  difficulty  in obtaining  adequate
supplies. For the year ended December 31, 2002, oil represented approximately 1%
of our fuel supply.

     For additional  information on our fuel supply,  see Results of Operations,
Liquidity and Capital  Resources,  Effects of Inflation and Changing  Prices and
Quantitative  and  Qualitative  Disclosures  About  Market Risk in

                                        6



Management's  Discussion  and  Analysis of  Financial  Condition  and Results of
Operations and Notes 1, 3, 14 and 15 to our Consolidated Financial Statements of
the 2002 Annual Report pages incorporated  herein by reference under Items 7 and
8.


INDUSTRY ISSUES

     We are facing  issues  common to the electric  and gas utility  industries.
These issues include:

     o    the potential for more intense competition;
     o    the potential for changes in the structure of regulation;
     o    changes in the  structure  of the  industry  as a result of changes in
          federal  and  state  laws,  including  the  formation  of  unregulated
          generating entities and regional transmission organizations;
     o    weak power prices due to overbuilt capacity and a weak economy;
     o    numerous troubled  companies within the energy sector and their impact
          on energy marketing and access to the capital markets;
     o    on-going consideration ofadditional changes of the industry by federal
          and state authorities;
     o    continually  developing  environmental  laws,  regulations and issues,
          including proposed new air quality standards;
     o    public concern about the siting of new facilities;
     o    proposals for demand-side management programs;
     o    public  concerns  about  nuclear  decommissioning  and the disposal of
          nuclear wastes; and
     o    global climate issues.

     We are monitoring  these issues and are unable to predict at this time what
impact, if any, these issues will have on our operations, financial condition or
liquidity.  For additional  information,  see Outlook and Regulatory  Matters in
Management's  Discussion  and  Analysis of  Financial  Condition  and Results of
Operations and Notes 2 and 14 to our  Consolidated  Financial  Statements of the
2002 Annual Report pages incorporated herein by reference under Items 7 and 8.

OPERATING STATISTICS

     The  information  on  pages  66  and  67  in  our  2002  Annual  Report  is
incorporated herein by reference.


AVAILABLE INFORMATION

     We  make   available   free  of  charge   through  our   Internet   website
(http://www.ameren.com)  our annual  report on Form 10-K,  quarterly  reports on
Form 10-Q,  current  reports on Form 8-K, and any  amendments  to those  reports
filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange
Act of 1934 as soon as reasonably  practicable after we electronically file such
reports  with,  or furnish  it to, the SEC.  This  information  for  AmerenCIPS,
AmerenUE, CILCORP,  AmerenCILCO and Generating Company is also available through
our Internet website.

     We also make available free of charge through our Internet website our code
of business  conduct for our directors,  officers and employees,  referred to as
our Corporate  Compliance Policy.  This document is also available in print upon
written request to Secretary, P.O. Box 66149, St. Louis, Missouri 63166-6149.

ITEM 2.  PROPERTIES.

     For  information  on  our  principal   properties,   planned  additions  or
replacements  and  transfers,  see the  generating  facilities  tables below and
Liquidity  and  Capital   Resources  and  Regulatory   Matters  in  Management's
Discussion  and Analysis of Financial  Condition and Results of  Operations  and
Notes 2, 8 and 14 to our  Consolidated  Financial  Statements of the 2002 Annual
Report pages incorporated  herein by reference under Items 7 and 8. Future plans
regarding  additional  electric  generating  facilities  referred to in the 2002
Annual Report are subject to change,  including increasing or decreasing planned
or installed future generating capacity, based on market conditions,  regulatory
approvals  for  additions,  our results of operations  and financial  condition,
availability of financing and other factors determined by management.

                                       7



     We are a member of MAIN (Mid-America  Interconnected Network), which is one
of the ten regional electric reliability councils organized for coordinating the
planning  and  operation  of the  nation's  bulk  power  supply.  MAIN  operates
primarily in Wisconsin, Michigan, Illinois and Missouri.

     Our bulk  power  system is  operated  as an  Ameren-wide  control  area and
transmission  system under the  FERC-approved  amended joint dispatch  agreement
between AmerenUE,  Generating Company and AmerenCIPS. The amended joint dispatch
agreement  provides a basis upon  which  AmerenUE  and  Generating  Company  can
participate  in  the   coordinated   operation  of  AmerenCIPS'  and  AmerenUE's
transmission  facilities  with  AmerenUE's and Generating  Company's  generating
facilities  in order to  achieve  economies  consistent  with the  provision  of
reliable  electric service and an equitable sharing of the benefits and costs of
that coordinated  operation.  In 2002, we had more than 30 interconnections  for
transmission  service and the exchange of electric energy,  directly and through
the  facilities  of others.  AmerenCILCO  is  currently  expected to continue to
operate as a separate  control area. As such, its generating  plants will not be
jointly  dispatched with the generating  plants owned by AmerenUE and Generating
Company.  AmerenCILCO is a transmission owning member of the Midwest Independent
System  Operating  (Midwest ISO) and has transferred  functional  control of its
system to the Midwest ISO. Transmission service on the AmerenCILCO  transmission
system  is  provided  pursuant  to the  terms of the  Midwest  ISO  open  access
transmission  tariff on file with the FERC. For  information on AmerenCIPS'  and
AmerenUE's  participation  in the Midwest  ISO,  see Note 2 to our  Consolidated
Financial  Statements  of the 2002 Annual  Report pages  incorporated  herein by
reference under Item 8.

     The  following  tables set forth  information  with respect to our electric
generating  facilities  and  capability  at the time of our  expected  2003 peak
summer electrical demand:



                                                         AmerenUE Generating Facilities
                                                         ------------------------------
             Primary
             Fuel            Name of                                                    Net Kilowatt          Net
             Source           Plant                         Location                    Capability(a)     Heat Rate(l)
             -------         -------                        --------                    -------------     ------------
                                                                                               
             Coal          Labadie                     Franklin County, MO                 2,400,000         10,210
                           Rush Island                 Jefferson County, MO                1,187,000         10,580
                           Sioux                       St. Charles County, MO                959,000          9,700
                           Meramec                     St. Louis County, MO                  816,000         11,206
                                                                                         -----------
                                                       Total Coal                          5,362,000

             Nuclear       Callaway                    Callaway County, MO                 1,136,000         10,494

             Hydro         Osage                       Lakeside, MO                          226,000           N/A
                           Keokuk                      Keokuk, IA                            134,000           N/A
                                                                                         -----------
                                                       Total Hydro                           360,000

             Pumped-
             storage       Taum Sauk                   Reynolds County, MO                   440,000           N/A

             Oil           Venice CT(b) 1              Venice, IL                             25,000         14,380
                           Howard Bend CT              St. Louis County, MO                   43,000         11,899
                           Fairgrounds CT                Jefferson City, MO                   55,000         11,100
                           Mexico CT                   Mexico, MO                             55,000         11,100
                           Moberly CT                  Moberly, MO                            55,000         11,100
                           Moreau CT                   Jefferson City, MO                     55,000         11,100
                           Meramec CT 1                St. Louis County, MO                   55,000         11,100
                                                                                       -------------
                                                       Total Oil                             343,000



                                       8





                                                         AmerenUE Generating Facilities (Continued)
                                                         ------------------------------------------
             Primary
             Fuel            Name of                                                    Net Kilowatt          Net
             Source           Plant                         Location                    Capability(a)     Heat Rate(l)
             -------         -------                        --------                    -------------     ------------
                                                                                               
             Natural       Kirksville CT               Kirksville, MO                         13,000         18,811
               Gas         Viaduct CT                  Cape Girardeau, MO                     25,000         15,137
                           Meramec CT 2 (c)            St. Louis County, MO                   53,000         12,031
                           Venice CT 2                 Venice, IL                             48,000          9,800
                           Peno Creek CTs 1
                                through 4(d)           Bowling Green, MO                     188,000         10,878
                                                                                       -------------
                                                       Total Natural Gas                     327,000

                                                              TOTAL                      7,968,000(e)




                                                        Electric Energy, Inc. Generating Facilities(m)
                                                        ----------------------------------------------
             Primary
             Fuel            Name of                                                    Net Kilowatt          Net
             Source           Plant                         Location                    Capability(a)     Heat Rate(l)
             -------         -------                        --------                    -------------     ------------
                                                                                               
             Coal          Joppa Generating Station    Joppa, IL                             600,000         10,347

             Natural       Joppa (Units 4-5)           Joppa, IL                              44,000         12,200
              Gas                                                                       -------------

                                                              TOTAL                          644,000





                                                          Generating Company Generating Facilities
                                                          ----------------------------------------
             Primary
             Fuel            Name of                                                    Net Kilowatt          Net
             Source           Plant                         Location                    Capability(a)     Heat Rate(l)
             -------         -------                        --------                    -------------     ------------
                                                                                               
             Coal          Newton(f)                   Newton, IL                          1,134,000         10,403
                           Coffeen(f)                  Coffeen, IL                           900,000         10,368
                           Hutsonville(f)
                             (Units 3 & 4)             Hutsonville, IL                       153,000         10,371
                           Meredosia(f)
                            (Unit 3)                   Meredosia, IL                         215,000         11,063
                                                                                         -----------
                                                       Total Coal                          2,402,000

             Oil           Meredosia(f)
                             (Unit 4)                  Meredosia, IL                         186,000         11,186
                           Hutsonville(f)
                             (Diesel)                  Hutsonville, IL                         3,000         11,408
                                                                                       -------------
                                                       Total Oil                             189,000

             Natural       Gibson City CTs 1 & 2(c)    Gibson City, IL                       234,000         11,490
                 Gas       Pinckneyville CTs
                                1 through 8            Pinckneyville, IL                     320,000         10,921
                           Kinmundy CTs 1 & 2(c)       Kinmundy, IL                          232,000         11,488
                           Grand Tower CTs 1 & 2(g)    Grand Tower, IL                       516,000          7,515
                           Joppa 7B CTs 1, 2 & 3(h)    Joppa, IL                             162,000         11,550
                           Elgin CTs 1 through 4       Elgin, IL                             468,000         11,488
                           Columbia CTs
                                1 through 4            Columbia, MO                          140,000         12,298
                                                                                         -----------
                                                       Total Natural Gas                   2,072,000

                                                              TOTAL                        4,663,000(e, i)


                                       9






                                                                AmerenCILCO Generating Facilities
                                                                ---------------------------------
             Primary
             Fuel            Name of                                                    Net Kilowatt          Net
             Source           Plant                         Location                    Capability(a)     Heat Rate(l)
             -------         -------                        --------                    -------------     ------------
                                                                                               

             Coal            Duck Creek                Canton, IL                            366,000         10,018
                             E.D. Edwards
                             (Units 1-3)               Bartonville, IL                       740,000          9,863
                                                                                       -------------

                                                       Total Coal                          1,106,000


             Oil           Kickapoo (Units 1-8)        Lincoln, IL                            13,000         10,388
                           Hallock (Units 1-8)         Peoria, IL                             13,000          5,300
                                                                                      --------------

                                                       Total Oil                              26,000


             Natural       Sterling CTs (Units 1 & 2)  Peoria, IL                             30,000          14,385
                 Gas       Indian Trails (Co-Gen)      Pekin, IL                              10,000          10,018
                                                                                          ----------

                                                       Total Gas                              40,000

                                                              TOTAL                        1,172,000




                                                            AmerenEnergy Medina Valley Co-Generating Facilities
                                                            ---------------------------------------------------
             Primary
             Fuel            Name of                                                    Net Kilowatt          Net
             Source           Plant                         Location                    Capability(a)     Heat Rate(l)
             -------         -------                        --------                    -------------     ------------
                                                                                              
             Natural       Medina Valley (Co-Gen)         Mossville, IL                       38,000          5,322
               Gas


     (a)  "Net Kilowatt Capability" represents generating capacity available for
          dispatch from the facility into the electric transmission grid.
     (b)  The abbreviation "CT" represents combustion turbine generating unit.
     (c)  CT has the  capability of operating on either oil or natural gas (dual
          fuel).
     (d)  For information regarding a lease arrangement applicable to these CTs,
          see Note 8 to our Consolidated Financial Statements of the 2002 Annual
          Report pages incorporated herein by reference under Item 8.
     (e)  Approximately 550 megawatts of generating capacity  (Pinckneyville CTs
          1  through  8 and  Kinmundy  CTs 1 and 2) are  expected  to be sold by
          Generating  Company  to  AmerenUE  subject  to  receipt  of  necessary
          regulatory approvals.
     (f)  Facilities were transferred to Generating Company by AmerenCIPS on May
          1, 2000 (see Item 1. Business - General above).
     (g)  The  Grand  Tower  Plant,  which  was  a  coal  plant  transferred  to
          Generating  Company by AmerenCIPS on May 1, 2000,  has been  repowered
          with two gas-fired CTs.
     (h)  These CTs are owned by  Generating  Company  and leased to its parent,
          AmerenEnergy Development Company. The operating lease is for a minimum
          term of 15 years  expiring  September  30,  2015.  Generating  Company
          receives rental payments under the lease in fixed monthly amounts that
          vary over the term of the lease and range from $0.8 - $1.0 million.
     (i)  Excludes  approximately  126  megawatts of two  coal-fired  generating
          units at Generating Company's Meredosia facility which were mothballed
          in December 2002.
     (j)  We acquired  ownership of these generating plants with our acquisition
          of CILCORP from AES on January 31, 2003.
     (k)  We acquired ownership of this generating plant with our acquisition of
          AES Medina Valley Cogen (No. 4), LLC from AES on February 4, 2003.

                                       10



     (l)  "Net Heat  Rate"  represents  the  amount of energy to produce a given
          unit of output and is expressed as BTU per kilowatthour.
     (m)  Ameren owns a 60% ownership interest in EEI.

     As of December 31, 2002, AmerenCIPS owned approximately 1,900 circuit miles
of electric transmission lines.  AmerenCIPS operates one propane-air plant, four
underground  gas  storage  fields and  approximately  4,900 miles of natural gas
transmission  and  distribution  mains. As of December 31, 2002,  AmerenUE owned
approximately  3,200  circuit  miles of electric  transmission  lines.  AmerenUE
operates three  propane-air  plants and 2,900 miles of gas mains. As of December
31,  2002,  AmerenCILCO  owned  approximately  333  circuit  miles  of  electric
transmission lines.  AmerenCILCO operates two underground gas storage fields and
approximately  3,674 miles of gas  transmission and  distribution  mains.  Other
properties of the  companies  include  distribution  lines,  underground  cable,
office buildings, warehouses, garages and repair shops.

     Substantially  all of the properties and plant of AmerenCIPS,  AmerenUE and
AmerenCILCO  are subject to the direct  first liens of the  indentures  securing
their first mortgage  bonds. On May 1, 2000,  AmerenCIPS  transferred all of its
generating  facilities  and related assets to Generating  Company.  As a part of
this transfer,  AmerenCIPS' generating property and plant were released from the
lien of the indenture  securing its first  mortgage  bonds and such property and
plant are  presently  unencumbered.  For  additional  information  on this asset
transfer,  see General  section  under Item 1.  Business  herein.  During  2003,
AmerenCILCO plans to transfer substantially all of its generating facilities and
related assets to its non rate-regulated electric generating subsidiary, Central
Illinois Generation,  Inc. (CIGI). CIGI was incorporated in Illinois in November
2001  in   conjunction   with  the  Illinois  Law.  As  part  of  the  transfer,
AmerenCILCO's  generating  property and plant will be released  from the lien of
the indenture securing its first mortgage bonds.

     We  indirectly  own 60% of the  common  stock  of EEI,  which  owns  and/or
operates electric generation and transmission facilities in Illinois that supply
electric  power  primarily  to a uranium  enrichment  plant  located in Paducah,
Kentucky.  AmerenUE owns 40% of the common stock of EEI, and  Resources  Company
owns 20% of such stock.  On April 30,  2002,  AmerenCIPS  transferred  their 20%
common  stock  interest  in EEI to Ameren in the form of a non-cash  dividend of
common stock in EEI.  The book value of  AmerenCIPS  investment  in EEI was $1.8
million. Subsequently,  Ameren contributed such stock to Resources Company. This
transfer  completed the process of achieving a full  divestiture of all electric
generating  capacity  that had been owned  directly or  indirectly by AmerenCIPS
pursuant to restructuring  of the Illinois power industry.  The remaining 40% of
the  common  stock of EEI is held 20% each by  Kentucky  Utilities  Company  and
Illinova Generating Company.


ITEM 3.  LEGAL PROCEEDINGS.

     We are  involved in legal and  administrative  proceedings  before  various
courts and agencies  with respect to matters  arising in the ordinary  course of
business,  some of which involve substantial  amounts. We believe that the final
disposition of these  proceedings,  except as otherwise noted in the 2002 Annual
Report pages incorporated herein by reference under Items 7 and 8, will not have
a material  adverse effect on our financial  position,  results of operations or
liquidity.

Waste Disposal

     On July 30, 2002, the Illinois Attorney General's Office advised us that it
would be commencing an enforcement  action concerning an inactive waste disposal
site near  Coffeen,  Illinois,  which is the  location  of a  disposal  facility
permitted by the  Illinois  Environmental  Protection  Agency to receive fly ash
from the Coffeen power plant.  The Illinois  Attorney  General also notified the
disposal  facility's  current and former  owners as to the proposed  enforcement
action. The Attorney General advised that it may initiate an action under CERCLA
to recover past costs incurred at the site  (approximately  $0.3 million) and to
obtain  a  declaratory  judgment  as to  liability  for  future  costs.  Neither
Generating  Company,   the  current  owner  of  the  Coffeen  power  plant,  nor
AmerenCIPS,  the prior owner of the Coffeen  power plant,  owned or operated the
disposal facility.  We believe that this matter will not have a material adverse
effect on Ameren's financial position, results of operations or liquidity.

Marketing Company - AmerenUE Power Supply Agreements

     In order to satisfy  AmerenUE's  regulatory load  requirements for 2001 and
2002,  AmerenUE  purchased,  under a one-year contract 450 megawatts of capacity
and energy (the 2001 Marketing  Company - AmerenUE  agreement) and 200 megawatts
of capacity and energy (the 2002 Marketing  Company - AmerenUE  agreement)  from
Marketing  Company.  These  agreements  were entered into through a  competitive
bidding process and reflected  market-based

                                       11



rates.  Generating  Company  supplied the power for these  agreements  under its
power supply agreement with Marketing Company.

     The FERC accepted the 2001 Marketing Company - AmerenUE agreement as filed.
The 2002 Marketing Company - AmerenUE agreement was set for hearing to determine
that  the  contract  terms  were  just and  reasonable.  On March  12,  2003,  a
settlement between Marketing Company and the FERC Staff was approved by the FERC
effectively  resolving  all  issues  concerning  the 2002  Marketing  Company  -
AmerenUE  agreement  set for hearing.  While the FERC order  contains a standard
refund report requirement, no refunds are due under the settlement as approved.

     In May 2001 and May 2002, the MoPSC filed  complaints with the SEC relating
to these agreements.  While the complaints were pending,  the MoPSC and AmerenUE
reached an agreement for resolving these disputes.  The agreement requires us to
not enter into any new contracts to purchase  wholesale electric energy from any
Ameren affiliate that is an exempt wholesale  generator without first obtaining,
on a timely basis, the  determinations  required of the MoPSC that are specified
in Section  32(k) of PUHCA.  However,  this  commitment  did not prevent us from
completing the purchases  contemplated by the 2001 and 2002 Marketing  Company -
AmerenUE  agreements  and does not  prevent us from  making  short  term  energy
purchases  (less than 90 days) from an Ameren  affiliate,  without  prior  MoPSC
determination,  to  prevent or  alleviate  system  emergencies.  As part of this
agreement, the MoPSC has agreed to terminate its SEC complaints.

Regional Transmission Organization (RTO)

     For  information  on  our  participation  in a  RTO,  see  Note  2  to  our
Consolidated  Financial  Statements of the 2002 Annual Report pages incorporated
herein by reference under Item 8. GridAmerica is scheduled to become operational
in spring 2003. Our  participation  in GridAmerica is subject to MoPSC approval.
An order from the MoPSC is expected during the third quarter of 2003.

     For additional  information on legal and  administrative  proceedings,  see
Rates and Regulation under Item 1 herein and Liquidity and Capital Resources and
Regulatory  Matters  in  Management's   Discussion  and  Analysis  of  Financial
Condition and Results of Operations  and Notes 2, 14 and 18 to our  Consolidated
Financial  Statements  of the 2002 Annual  Report pages  incorporated  herein by
reference under Items 7 and 8.

FORWARD-LOOKING STATEMENTS

     Statements made in this report which are not based on historical facts, are
"forward-looking"  and, accordingly,  involve risks and uncertainties that could
cause actual results to differ  materially from those  discussed.  Although such
"forward-looking"  statements  have  been  made in good  faith  and are based on
reasonable assumptions,  there is no assurance that the expected results will be
achieved.  These statements include (without limitation) statements as to future
expectations,  beliefs, plans, strategies,  objectives,  events, conditions, and
financial  performance.  In connection with the "safe harbor"  provisions of the
Private  Securities  Litigation  Reform  Act  of  1995,  we are  providing  this
cautionary  statement to identify some important factors that could cause actual
results to differ materially from those anticipated.  The following factors,  in
addition  to  those  discussed  elsewhere  in  this  report  and  in  subsequent
securities  filings,  could cause results to differ  materially  from management
expectations as suggested by such "forward-looking" statements:

o    the effects of the  stipulation  and  agreement  relating  to the  AmerenUE
     Missouri  electric  excess  earnings  complaint  case and other  regulatory
     actions, including changes in regulatory policy;
o    changes in laws and other  governmental  actions,  including  monetary  and
     fiscal policies;
o    the impact on us of current  regulations  related  to the  opportunity  for
     customers to choose alternative energy suppliers in Illinois;
o    the  effects of  increased  competition  in the future due to,  among other
     things,  deregulation  of certain aspects of our business at both the state
     and federal levels;
o    the  effects of  participation  in a FERC  approved  Regional  Transmission
     Organization,  including activities associated with the Midwest Independent
     System Operator;
o    availability  and  future  market  prices  for  fuel and  purchased  power,
     electricity and natural gas,  including the use of financial and derivative
     instruments and volatility of changes in market prices;
o    the cost of  commodities,  such as natural gas,  used in the  production of
     electricity and our ability to recover such increased cost;
o    average rates for electricity in the Midwest;

                                       12



o    business and economic conditions;
o    the impact of the adoption of new accounting  standards on the  application
     of appropriate technical accounting rules and guidance;
o    interest rates and the availability of capital;
o    actions of rating agencies and the effects of such actions;
o    weather conditions;
o    generation plant construction, installation and performance;
o    operation of nuclear power facilities and decommissioning costs;
o    the  effects  of  strategic   initiatives,   including   acquisitions   and
     divestitures;
o    the impact of current environmental regulations on utilities and generating
     companies and the  expectation  that more  stringent  requirements  will be
     introduced over time,  which could  potentially  have a negative  financial
     effect;
o    future wages and employee  benefits costs  including  changes in returns of
     benefit plan assets;
o    disruptions  of the capital  markets or other  events  making our access to
     necessary capital more difficult or costly;
o    competition from other generating  facilities including new facilities that
     may be developed in the future;
o    difficulties in integrating CILCO with Ameren's other businesses;
o    changes in the coal markets,  environmental  laws or  regulations  or other
     factors  adversely  impacting  synergy  assumptions in connection  with the
     CILCORP acquisition;
o    cost and availability of transmission  capacity for the energy generated by
     our  generating  facilities  or  required to satisfy  energy  sales made by
     Ameren; and
o    legal and administrative proceedings.

     Given these  uncertainties,  undue  reliance  should not be placed on these
"forward-looking"   statements.   Except  to  the  extent  required  by  federal
securities  laws, we undertake no  obligation  to publicly  update or revise any
"forward-looking"  statements,  whether as a result of new  information,  future
events or otherwise.


ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

     There were no matters  submitted to a vote of security  holders  during the
fourth quarter of 2002.


INFORMATION  REGARDING  EXECUTIVE OFFICERS REQUIRED BY ITEM 401(b) OF REGULATION
S-K:

                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
Ameren Corporation
------------------
Charles W. Mueller          64      Chairman,
                                    Chief Executive Officer,        12/31/97
                                    and Director

Mr. Mueller began his career with AmerenUE in 1961 as an engineer.  He was named
Treasurer  in 1978,  Vice  President-Finance  in 1983,  Senior Vice  President -
Administrative  Services in 1988,  President in 1993 and Chief Executive Officer
in 1994. Mr. Mueller was elected Chairman, President and Chief Executive Officer
of Ameren in 1997.  He  relinquished  his  position as  President  of Ameren and
AmerenUE  in 2001.  Mr.  Mueller  is also an  officer  at  various  of our other
subsidiaries.

Gary L. Rainwater           56      President and
                                    Chief Operating Officer          8/30/01

Mr.  Rainwater  began his career with  AmerenUE in 1979 as an  engineer.  He was
named General  Manager - Corporate  Planning in 1988 and Vice President in 1993.
Mr. Rainwater was elected Executive Vice President of AmerenCIPS in January 1997
and was named to his present  position as President and Chief Operating  Officer
of AmerenCIPS in December  1997.  He was elected  President and Chief  Operating
Officer of Ameren in 2001.  Mr.  Rainwater  is also an officer at various of our
other subsidiaries.

                                       13



Warner L. Baxter            41      Senior Vice President            8/30/01
                                    (Principal Financial Officer)

From  1983  to  1995,  Mr.  Baxter  was  employed  by  Price   Waterhouse   (now
PricewaterhouseCoopers  LLP).  Mr. Baxter  joined  AmerenUE in 1995 as Assistant
Controller.  He was promoted to  Controller  of AmerenUE in 1996 and was elected
Vice  President and  Controller  of AmerenUE and Ameren in 1998.  Mr. Baxter was
elected to his present position at Ameren in 2001. Mr. Baxter is also an officer
at various of our other subsidiaries.

Jerre E. Birdsong           48      Vice President                  10/12/01
                                    and Treasurer                    4/23/96

Mr.  Birdsong  joined  AmerenUE  in 1977 as an  economist.  He was  promoted  to
Assistant  Treasurer  in  1984,  Manager  of  Finance  in 1989  and in 1993  was
appointed as Treasurer of AmerenUE.  He was elected Treasurer of Ameren in 1996.
In addition to being Treasurer, he was elected to the position of Vice President
in 2001. Mr. Birdsong is also an officer at various of our other subsidiaries.

Martin J. Lyons             36      Vice President                   2/14/03
                                    and Controller                  10/22/01
                                    (Principal Accounting Officer)

Mr. Lyons was  appointed as Controller of Ameren in October 2001. In addition to
being  Controller,  he was elected to the position of Vice President in 2003. He
was  previously  employed  by  PricewaterhouseCoopers  LLP  for 13  years,  most
recently  as a  partner.  Mr.  Lyons is also an  officer at various of our other
subsidiaries.

Steven R. Sullivan          42      Vice President Regulatory Policy,
                                    General Counsel                   7/1/98
                                    and Secretary                     9/1/98

Mr. Sullivan was elected Vice President, General Counsel and Secretary of Ameren
in 1998. He was  previously  employed by Anheuser  Busch  Companies,  Inc. as an
attorney  from 1995 to 1998.  Mr.  Sullivan is also an officer at various of our
other subsidiaries.
                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
AmerenUE (Subsidiary)
---------------------
Charles W. Mueller          64      Chairman,                         8/30/01
                                    Chief Executive Officer,           1/1/94
                                    and Director                      6/11/93

Gary L. Rainwater           56      President and Chief Operating     8/30/01
                                    Officer and Director              4/28/98

Paul A. Agathen             55      Senior Vice President            10/12/01
                                    and Director                      4/28/98

Warner L. Baxter            41      Senior Vice President             8/30/01
                                    and Director                      4/22/99

Daniel F. Cole              49      Senior Vice President             7/12/99

Garry L. Randolph           54      Senior Vice President            10/16/00

Thomas R. Voss              55      Senior Vice President              6/1/99
                                    and Director                     10/25/01

David A. Whiteley           46      Senior Vice President             8/30/01

Ronald D. Affolter          49      Vice President                   10/16/00

                                       14




Jerre E. Birdsong           48      Vice President                   10/12/01
                                    and Treasurer                      7/1/93

Martin J. Lyons             36      Vice President                    2/14/03
                                    and Controller                   10/22/01

Michael J. Montana*         56      Vice President                     7/1/88

Charles D. Naslund          50      Vice President                     2/1/99

William C. Shores*          64      Vice President                     7/1/88

Steven R. Sullivan          42      Vice President Regulatory Policy,
                                    General Counsel                    7/1/98
                                    and Secretary                      9/1/98

Ronald C. Zdellar           58      Vice President                     9/1/02

                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
AmerenCIPS (Subsidiary)
-----------------------
Gary L. Rainwater           56      President and Chief Operating     1/1/98
                                    Officer and Director             12/2/97

Paul A. Agathen             55      Senior Vice President           10/12/01
                                    and Director                    12/31/97

Warner L. Baxter            41      Senior Vice President            8/30/01
                                    and Director                     4/22/99

Daniel F. Cole              49      Senior Vice President           10/12/01

Garry L. Randolph           54      Senior Vice President           10/12/01

Thomas R. Voss              55      Senior Vice President             6/1/99
                                    and Director                    10/12/01

David A. Whiteley           46      Senior Vice President           10/12/01

Jerre E. Birdsong           48      Vice President                  10/12/01
                                    and Treasurer                   12/31/97

J. L. Davis                 55      Vice President                    2/1/03

Martin J. Lyons             36      Vice President                   2/14/03
                                    and Controller                  10/22/01

Michael J. Montana*         56      Vice President                   4/28/98

Gilbert W. Moorman*         59      Vice President                    6/1/88

Craig D. Nelson             49      Vice President                   4/28/98

Steven R. Sullivan          42      Vice President Regulatory Policy,
                                    General Counsel
                                    and Secretary                    11/7/98

                                       15



                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
Ameren Services Company Subsidiary)
-----------------------------------

Charles W. Mueller          64     Chairman,                         8/30/01
                                   Chief Executive Officer,          11/4/97
                                   and Director

Gary L. Rainwater           56     President and Chief Operating     8/30/01
                                   Offier and Director               4/25/00

Paul A. Agathen             55     Senior Vice President            12/31/97
                                   and Director                      4/27/99

Warner L. Baxter            41     Senior Vice President             8/30/01
                                   and Director                      4/25/00

Daniel F. Cole              49     Senior Vice President              6/1/99

Thomas R. Voss              55     Senior Vice President              6/1/99
                                   and Director                     10/25/01

David A. Whiteley           46     Senior Vice President             8/30/01

Jerre E. Birdsong           48     Vice President                   10/12/01
                                   and Treasurer                    12/31/97

Mark C. Birk                38     Vice President                    2/14/03

Charles A. Bremer           58     Vice President                   12/31/97

J. L. Davis                 55     Vice President                   12/31/97

Martin J. Lyons             36     Vice President                    2/14/03
                                   and Controller                   10/22/01

Richard J. Mark             47     Vice President                     1/2/02

Donna K. Martin             55     Vice President                    5/15/02

Michael L. Menne            48     Vice President                     9/1/02

Michael J. Montana*         56     Vice President                    2/31/97

Michael G. Mueller          39     Vice President                    9/18/00

Craig D. Nelson             49     Vice President                    2/31/97

Gregory L. Nelson           45     Vice President                    2/16/99

J. Kay Smith                57     Vice President                     7/1/99

Steven R. Sullivan          42     Vice President Regulatory Policy,
                                   General Counsel                    7/1/98
                                   and Secretary                      9/1/98

Samuel E. Willis            58     Vice President                   12/31/97

                                       16



Ronald C. Zdellar           58     Vice President                   12/31/97


                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
AmerenEnergy, Inc. (Subsidiary)
-------------------------------

Daniel F. Cole              49     President                         1/1/03

Jerre E. Birdsong           48     Vice President                  10/12/01
                                   and Treasurer                    9/15/98

Clarence J. Hopf            46     Vice President                   6/14/99

Steven R. Sullivan          42     Vice President Regulatory Policy,
                                   General Counsel
                                   and Secretary                    9/15/98


                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
AmerenEnergy Resources Company (Subsidiary)
-------------------------------------------

Daniel F. Cole              49      President                       8/30/01
                                    and Director                    9/15/99

Jerre E. Birdsong           48      Vice President                 10/12/01
                                    and Treasurer                   9/15/99

R. Alan Kelley              50      Vice President                 11/13/00

Michael L. Moehn            33      Vice President                   9/1/02

Steven R. Sullivan          42      Vice President Regulatory Policy,
                                    General Counsel
                                    and Secretary                   9/15/99


                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
AmerenEnergy Generating Company (Subsidiary)
--------------------------------------------

Daniel F. Cole              49      President                       8/30/01
                                    and Director                     3/2/00

Paul A. Agathen             55      Senior Vice President          10/12/01
                                    and Director                     3/2/00

Warner L. Baxter            41      Senior Vice President           8/30/01
                                    and Director                   10/25/01

R. Alan Kelley              50      Senior Vice President            3/2/00

Garry L. Randolph           54      Senior Vice President          10/12/01

                                       17



                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
AmerenEnergy Generating Company
(Subsidiary) (Continued)
-------------------------------

Thomas R. Voss              55      Senior Vice President          10/12/01

David A. Whiteley           46      Senior Vice President          10/12/01

Jerre E. Birdsong           48      Vice President                 10/12/01
                                    and Treasurer                    3/2/00

Martin J. Lyons             36      Vice President                  2/14/03
                                    and Controller                 10/22/01

Michael J. Montana*         56      Vice President                  11/6/00

Robert L. Powers            54      Vice President                   7/5/00

Jerry L. Simpson            46      Vice President                   3/2/00

Steven R. Sullivan          42      Vice President Regulatory Policy,
                                    General Counsel
                                    and Secretary                    3/2/00


                                                              Date First Elected
                          Age At    Present Position and        or Appointed to
       Name              12/31/02   Business Experience        Present Position
       ----              --------   --------------------      ------------------
AmerenEnergy Fuels and
Services Company (Subsidiary)
-----------------------------

Daniel F. Cole              49      President                       8/30/01
                                    and Director                    9/18/00

Warner L. Baxter            41      Senior Vice President           8/30/01
                                    and Director                   10/25/01

Jerre E. Birdsong           48      Vice President                 10/12/01
                                    and Treasurer                   9/18/00

Martin J. Lyons             36      Vice President                  2/14/03
                                    and Controller                 10/22/01

Michael G. Mueller          39      Vice President                  9/18/00

Steven R. Sullivan          42      Vice President Regulatory Policy,
                                    General Counsel
                                    and Secretary                   9/18/00


* These individuals retired in 2003.

     All officers are elected or appointed  annually by the respective  Board of
Directors  of such  company  following  the election of such Board at the annual
meetings  of  shareholders.  There  are  no  family  relationships  between  the
foregoing  officers of Ameren  except that  Charles W.  Mueller is the father of
Michael G. Mueller. Except for Gregory L. Nelson, Steven R. Sullivan,  Martin J.
Lyons,  Richard  J.  Mark,  Michael  L.  Moehn and Donna K.  Martin  each of the
above-named  executive officers has been employed by us for more than five years
in executive or

                                       18



management  positions.  Mr. Nelson was previously  employed as a tax attorney by
the law firm of  Thelen  Reid & Priest  LLP;  Mr.  Sullivan  as an  attorney  by
Anheuser   Busch   Companies,    Inc.;   Mr.   Lyons   as   an   accountant   by
PricewaterhouseCoopers  LLP; Mr. Mark as Chief  Executive  Officer of St. Mary's
Hospital  by  Ancilla  Systems,  Incorporated;  Mr.  Moehn as an  accountant  by
PricewaterhouseCoopers  LLP;  and Ms.  Martin  in human  resources  by  Faulding
Pharmaceuticals.


                                     PART II

ITEM 5.  MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED SHAREHOLDER
         MATTERS.

     Information  required to be reported by this item is included  under Common
Stock and  Dividend  Information  on Page 69 of the 2002  Annual  Report  and is
incorporated herein by reference.


ITEM 6.  SELECTED FINANCIAL DATA.

     Information  for the 1998-2002  period required to be reported by this item
is included on Page 65 of the 2002 Annual Report and is  incorporated  herein by
reference.


ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
         RESULTS OF OPERATIONS.

     Information  required  to be  reported by this item is included on Pages 17
through 34 of the 2002 Annual Report and is incorporated herein by reference.


ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK.

     Information   required   to  be  reported  by  this  item  is  included  in
Management's  Discussion  and  Analysis of  Financial  Condition  and Results of
Operations  on  Pages  31  through  34 and  Notes  3 and 16 to our  Consolidated
Financial  Statements on Pages 46 and 47 and Pages 62 and 63,  respectively,  of
the 2002 Annual Report and is incorporated herein by reference.


ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA.

     Our  financial  statements  on Pages 35 through  64, the report  thereon of
PricewaterhouseCoopers  LLP  appearing  on Page 16 and  the  Selected  Quarterly
Information  on Page 67 of the 2002  Annual  Report are  incorporated  herein by
reference.

     Since the  acquisition  of CILCORP and CILCO on January 31,  2003,  we have
been  conducting  a review of their  financial  statements.  As a result of this
ongoing  review,   revenue,   operating  income,   net  income  from  continuing
operations,  and total  assets for 2002 and 2001 may change from the  disclosure
made on Page 64 of the 2002 Annual  Report in Note 18 - Subsequent  Event to our
Consolidated Financial Statements. CILCORP and AmerenCILCO intend to file a Form
12b-25 with the SEC on April 1, 2003 and file their respective Annual Reports on
Form 10-K within 15 calendar  days of March 31, 2003.  You should refer to these
filings,  for  any  changes  to  revenue,  operating  income,  net  income  from
continuing  operations,  and total assets, which are expected to be noncash, and
will have no impact on the  financial  statements  of Ameren or the  assumptions
upon which the CILCORP acquisition was based.


ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
         FINANCIAL DISCLOSURE.

     None.

                                       19



                                    PART III

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT.

     Information  concerning  directors  required to be reported by this item is
included  under Item (1):  Election of  Directors in our 2003  definitive  proxy
statement  filed  pursuant  to  Regulation  14A and is  incorporated  herein  by
reference.

     Information concerning executive officers required by this item is reported
in Part I of this Form 10-K.


ITEM 11. EXECUTIVE COMPENSATION.

     Information  required  to be  reported  by  this  item  is  included  under
Executive  Compensation in our 2003 definitive proxy statement filed pursuant to
Regulation 14A and is incorporated herein by reference.


ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT.

Equity Compensation Plan Information

     The  following  table  provides  information  as of December  31, 2002 with
respect to the shares of our common  stock that may be issued under our existing
equity compensation plan.




                                  Number of Securities to                                       Number of Securities Remaining
                                  be Issued upon Exercise       Weighted Average Exercise        Available for Future Issuance
                                  of Outstanding Options,          Price of Outstanding            Under Equity Compensation
Plan Category                       Warrants and Rights        Options, Warrants and Rights                  Plans
-----------------------------    --------------------------    -----------------------------    --------------------------------
                                                                                       
Equity Compensation Plans
Approved by Securityholders
(a)......                                  1,977,453                       $35.0965                        1,285,472(b)

Equity Compensation Plans
Not Approved by
Securityholders.........                     ------                          ------                            ------
-----------------------------    --------------------------    -----------------------------    --------------------------------

Total......................                1,977,453                       $35.0965                          1,285,472
-----------------------------    --------------------------    -----------------------------    --------------------------------


     (a)  Consists of the Ameren  Corporation  Long-Term  Incentive Plan of 1998
          which was approved by  shareholders in April 1998 and expires on April
          1, 2008.
     (b)  Excludes an aggregate of 449,422 restricted shares of our common stock
          issued under the Ameren Corporation  Long-Term  Incentive Plan of 1998
          in 2001, 2002 and 2003.

     Additional  information  required  to be  reported by this item is included
under Security  Ownership in our 2003 definitive  proxy statement filed pursuant
to Regulation 14A and is incorporated herein by reference.


ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS.

     Information  required to be  reported  by this item is included  under Item
(1): Election of Directors in our 2003 definitive proxy statement filed pursuant
to Regulation 14A and is incorporated herein by reference.


ITEM 14. CONTROLS AND PROCEDURES

     Within  90 days  prior  to the  date  of this  report,  we  carried  out an
evaluation,  under the  supervision  and with  participation  of our management,
including  our Chief  Executive  Officer  and Chief  Financial  Officer,  of the
effectiveness  of the  design  and  operation  of our  disclosure  controls  and
procedures pursuant to Rule 13a-14 under

                                       20



the Securities Exchange Act of 1934, as amended. Based upon that evaluation, the
Chief  Executive   Officer  and  Chief  Financial  Officer  concluded  that  our
disclosure  controls and  procedures  are  effective in timely  alerting them to
material  information relating to Ameren which is required to be included in our
periodic SEC filings.

     There have been no significant changes in our internal controls or in other
factors which could  significantly  affect internal  controls  subsequent to the
date we carried out our evaluation.

                                       21





                                     PART IV
                                                                                          
ITEM 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS
         ON FORM 8-K

     (A)  Financial Statements:

     (1)  Financial  Statements of Ameren  Corporation  which are required to be
          filed by Item 8 of this report

                                                                                                Page From 2002
                                                                                                 Annual Report (a)
                                                                                                ------------------

          Report of Independent Accountants.....................................................       16
          Consolidated Statement of Income - Years Ended December 31, 2002, 2001, and 2000             35
          Consolidated Balance Sheet - December 31, 2002 and 2001...............................       36
          Consolidated Statement of Cash Flows - Years Ended December 31, 2002, 2001, and 2000         37
          Consolidated Statement of Common Shareholders' Equity
             - Years Ended December 31, 2002, 2001, and 2000....................................       38
          Notes to Consolidated Financial Statements............................................    39-64

          (a) Incorporated by reference from the indicated pages of the 2002
Annual Report.

     (2)  Financial Statement Schedule
              The following schedule, for the years ended December 31, 2002,
              2001 and 2000, should be read in conjunction with the
              aforementioned financial state- ments (schedules not included have
              been omitted because they are not applicable or the required data
              is shown in the aforementioned financial statements).
                                                                                                  Pages Herein
                                                                                                  ------------
              Report of Independent Accountants on Financial
                 Statement Schedule.............................................................        30
              Valuation and Qualifying Accounts (Schedule II)...................................        31


     (3) Exhibits filed with this report are listed on the Exhibit Index

     (B) Reports on Form 8-K

               We filed a report on Form 8-K dated December 10, 2002,  providing
               (i) updated  information as to regulatory agency approvals of the
               CILCORP  acquisition;  (ii) the results of a voluntary retirement
               program  and  a  related  fourth  quarter  after  tax  charge  to
               earnings;  (iii)  information  regarding  pension  funding;  (iv)
               generating plant closure information and a related fourth quarter
               after-tax charge to earnings;  (v) updated information about FERC
               proceedings   relating  to  the   formation   and   operation  of
               GridAmerica LLC as an independent transmission company within the
               Midwest  Independent  System Operator;  (vi) a description of our
               comments to the FERC regarding its standard  market design notice
               of proposed rule making;  (vii) a discussion of risks  associated
               with our access to capital  markets;  (viii)  information  on our
               agreement  to sell  additional  shares of  common  stock in early
               2003; and (ix) the status of our labor agreements.

                                       22



     (C)  Exhibits

     Exhibit No.                   Description
     -----------                   -----------
       2.1          Stock purchase agreement, dated as of April 28, 2002, by and
                    between The AES Corporation (AES) and Ameren (March 31, 2002
                    Form 10-Q, Exhibit 2.1).

       2.2          Membership  Interest Purchase  Agreement,  dated as of April
                    28, 2002, by and between AES and Ameren (March 31, 2002 Form
                    10-Q, Exhibit 2.2).

       3.1(i)       Restated  Articles  of  Incorporation  of  Ameren  (File No.
                    33-64165, Annex F).

       3.2(i)       Certificate  of Amendment to Ameren's  Restated  Articles of
                    Incorporation filed with the Secretary of State of the State
                    of Missouri on  December  14, 1998 (1998 Form 10-K,  Exhibit
                    3(i)).

       3.3(ii)      By-Laws of Ameren as amended to December 31, 1997 (1997 Form
                    10-K, Exhibit 3(ii)).

       4.1          Indenture  of Mortgage  and Deed of Trust of AmerenUE  dated
                    June 15, 1937 (AmerenUE  Mortgage),  as amended May 1, 1941,
                    and Second  Supplemental  Indenture  dated May 1, 1941 (File
                    No. 2-4940, Exhibit B-1).


       4.2          Supplemental Indentures to the AmerenUE Mortgage

                    Dated as of                   File Reference                            Exhibit No.
                    -----------                   --------------                            -----------
                                                                                   
                    April 1, 1971          AmerenUE Form 8-K, April 1971                         6
                    February 1, 1974       AmerenUE Form 8-K, February 1974                      3
                    July 7, 1980           2-69821                                             4.6
                    December 1, 1991       33-45008                                            4.4
                    December 4, 1991       33-45008                                            4.5
                    January 1, 1992        AmerenUE Form 10-K, 1991                            4.6
                    October 1, 1992        AmerenUE Form 10-K, 1992                            4.6
                    December 1, 1992       AmerenUE Form 10-K, 1992                            4.7
                    February 1, 1993       AmerenUE Form 10-K, 1992                            4.8
                    May 1, 1993            AmerenUE Form 10-K, 1993                            4.6
                    August 1, 1993         AmerenUE Form 10-K, 1993                            4.7
                    October 1, 1993        AmerenUE Form 10-K, 1993                            4.8
                    January 1, 1994        AmerenUE Form 10-K, 1993                            4.9
                    February 1, 2000       AmerenUE Form 10-K, 2000                            4.1
                    August 15, 2002        AmerenUE Form 8-K, August 22, 2002                  4.3
                    March 5, 2003          AmerenUE Form 8-K, March 10, 2003                   4.4


       4.3          Indenture (for unsecured  subordinated  debt  securities) of
                    AmerenUE  dated as of December 1, 1996  (AmerenUE  1996 Form
                    10-K, Exhibit 4.36).

       4.4          Loan  Agreement  dated as of  December  1, 1991  between the
                    State   Environmental   Improvement  and  Energy   Resources
                    Authority  and AmerenUE,  together  with  Indenture of Trust
                    dated as of December 1, 1991 between the  Authority  and UMB
                    Bank,  N.A. as successor  trustee to Mercantile  Bank of St.
                    Louis, N.A. (AmerenUE 1992 Form 10-K, Exhibit 4.37).

       4.5          Loan  Agreement  dated as of December  1, 1992,  between the
                    State   Environmental   Improvement  and  Energy   Resources
                    Authority  and AmerenUE,  together  with  Indenture of Trust
                    dated as of December 1, 1992 between the  Authority  and UMB
                    Bank,  N.A. as successor  trustee to Mercantile  Bank of St.
                    Louis, N.A. (AmerenUE 1992 Form 10-K, Exhibit 4.38).

       4.6          Fuel Lease dated as of February 24, 1981  between  AmerenUE,
                    as lessee,  and Gateway Fuel  Company,  as lessor,  covering
                    nuclear fuel (AmerenUE 1980 Form 10-K, Exhibit 10.20).

                                       23



     Exhibit No.                   Description
     -----------                   -----------
       4.7          Amendments to Fuel Lease dated as of May 8, 1984 and October
                    15, 1984,  respectively,  between AmerenUE,  as lessee,  and
                    Gateway Fuel Company, as lessor, covering nuclear fuel (File
                    No. 2-96198, Exhibit 4.28).

       4.8          Amendment to Fuel Lease dated as of October 15, 1986 between
                    AmerenUE,  as lessee,  and Gateway Fuel Company,  as lessor,
                    covering  nuclear  fuel  (AmerenUE  September  30, 1986 Form
                    10-Q, Exhibit 4.3).

       4.9          Series  1998A Loan  Agreement  dated as of September 1, 1998
                    between  The  State  Environmental  Improvement  and  Energy
                    Resources  Authority  of the State of Missouri  and AmerenUE
                    (AmerenUE September 30, 1998 Form 10-Q, Exhibit 4.28).

       4.10         Series  1998B Loan  Agreement  dated as of September 1, 1998
                    between  The  State  Environmental  Improvement  and  Energy
                    Resources  Authority  of the State of Missouri  and AmerenUE
                    (AmerenUE September 30, 1998 Form 10-Q, Exhibit 4.29).

       4.11         Series  1998C Loan  Agreement  dated as of September 1, 1998
                    between  The  State  Environmental  Improvement  and  Energy
                    Resources  Authority  of the State of Missouri  and AmerenUE
                    (AmerenUE September 30, 1998 Form 10-Q, Exhibit 4.30).

       4.12         Indenture  dated as of August 15, 2002 from  AmerenUE to The
                    Bank of New York,  as Trustee,  relating  to senior  secured
                    debt securities  (including the forms of senior secured debt
                    securities as exhibits) (Ameren UE Form 8-K dated August 22,
                    2002, Exhibit 4.1).

       4.13         AmerenUE  Company  order dated August 22, 2002  establishing
                    the 5.25% Senior  Secured Notes due 2012  (AmerenUE Form 8-K
                    dated August 22, 2002, Exhibit 4.2).

       4.14         AmerenUE Company order dated March 10, 2003 establishing the
                    5.50% Senior Secured Notes due 2034 (AmerenUE Form 8-K dated
                    March 10, 2003, Exhibit 4.2).

       4.15         Indenture  of  Mortgage  or Deed of Trust  dated  October 1,
                    1941,  from Central  Illinois  Public Service  Company d/b/a
                    AmerenCIPS  (AmerenCIPS)  to Continental  Illinois  National
                    Bank and Trust  Company of Chicago and Edmond B. Stofft,  as
                    Trustees (U.S.  Bank Trust National  Association and Patrick
                    J. Crowley are  successor  Trustees.)  (Exhibit 2.01 in File
                    No. 2-60232).

       4.16         Supplemental  Indentures  dated,  respectively  September 1,
                    1947, January 1, 1949, February 1, 1952,  September 1, 1952,
                    June 1,  1954,  February  1, 1958,  January 1, 1959,  May 1,
                    1963, May 1, 1964, June 1, 1965, May 1, 1967, April 1, 1970,
                    April 1, 1971,  September 1, 1971, May 1, 1972,  December 1,
                    1973,  March  1,  1974,  April 1,  1975,  October  1,  1976,
                    November 1, 1976, October 1, 1978, August 1, 1979,  February
                    1, 1980,  February  1,  1986,  May 15,  1992,  July 1, 1992,
                    September 15, 1992,  April 1, 1993, June 1, 1995,  March 15,
                    1997,  June 1,  1997,  December  1,  1998 and  June 1,  2001
                    between  AmerenCIPS  and the Trustees under the Indenture of
                    Mortgage or Deed of Trust  referred to above as Exhibit 4.14
                    (Amended  Exhibit 7(b) in File No.  2-7341;  Second  Amended
                    Exhibit 7.03 in File No. 2-7795; Second Amended Exhibit 4.07
                    in File No. 2-9353; Amended Exhibit 4.05 in File No. 2-9802;
                    Amended  Exhibit 4.02 in File No.  2-10944;  Amended Exhibit
                    2.02 in File No.  2-13866;  Amended Exhibit 2.02 in File No.
                    2-14656;  Amended Exhibit 2.02 in File  No.2-21345;  Amended
                    Exhibit 2.02 in File No.  2-22326;  Amended  Exhibit 2.02 in
                    File No. 2-23569;  Amended Exhibit 2.02 in File No. 2-26284;
                    Amended  Exhibit 2.02 in File No.  2-36388;  Amended Exhibit
                    2.02 in File No.  2-39587;  Amended Exhibit 2.02 in File No.
                    2-41468;  Amended Exhibit 2.02 in File No. 2-43912;  Exhibit
                    2.03 in File No.  2-60232;  Amended Exhibit 2.02 in File No.
                    2-50146;  Amended Exhibit 2.02 in File No.  2-52886;  Second
                    Amended  Exhibit 2.04 in File No.  2-57141;  Amended Exhibit
                    2.04 in File No.  2-57557;  Amended Exhibit 2.06 in File No.
                    2-62564;  Exhibit  2.02(a)  in  File  No.  2-65914;  Amended
                    Exhibit  2.02(a) in File No.  2-66380;  and Amended  Exhibit
                    4.02 in File No.  33-3188;  Exhibit 4.02 to AmerenCIPS  Form
                    8-K dated May 15, 1992;  Exhibit 4.02 to AmerenCIPS Form 8-K
                    dated  July 1, 1992;  Exhibit  4.02 to  AmerenCIPS  Form 8-K
                    dated  September 15, 1992;  Exhibit 4.02 to AmerenCIPS  Form
                    8-K dated March 30, 1993;  Exhibit

                                       24



                    4.03 to AmerenCIPS Form 8-K dated June 5, 1995; Exhibit 4.03
                    to AmerenCIPS Form 8-K dated March 15, 1997; Exhibit 4.03 to
                    AmerenCIPS Form 8-K dated June 1, 1997;  Exhibit 4.2 in File
                    No. 333-59438;  Exhibit 4.1 to June 30, 2001 AmerenCIPS Form
                    10-Q.)

     Exhibit No.                   Description
     -----------                   -----------
       4.17         Agreement,  dated as of October 9, 1998,  between Ameren and
                    EquiServe Trust Company, N.A. (as successor to First Chicago
                    Trust Company of New York), as Rights Agent,  which includes
                    the form of  Certificate  of  Designation  of the  Preferred
                    Shares  as  Exhibit  A, the form of  Rights  Certificate  as
                    Exhibit B and the  Summary  of Rights as  Exhibit C (October
                    14, 1998 Form 8-K, Exhibit 4).

       4.18         Indenture  dated as of December 1, 1998 from  AmerenCIPS  to
                    The Bank of New York,  as Trustee,  relating to  AmerenCIPS'
                    Senior  Notes,  5.375% due 2008 and 6.125% due 2028 (Exhibit
                    4.4, in File No. 333-59438).

       4.19         Indenture  dated as of  November  1, 2000 from  AmerenEnergy
                    Generating Company  (Generating  Company) to The Bank of New
                    York,  as Trustee,  relating to the issuance of senior notes
                    (File No. 333-56594, Exhibit 4.1).

       4.20         First Supplemental Indenture dated as of November 1, 2000 to
                    Indenture  dated as of  November  1,  2000  from  Generating
                    Company to The Bank of New York,  as  Trustee,  relating  to
                    Generating  Company's 7.75% Senior Notes,  Series A due 2005
                    and  8.35%  Senior  Notes,  Series  B  due  2010  (File  No.
                    333-56594, Exhibit 4.2).

       4.21         Form of Second  Supplemental  Indenture dated as of June 12,
                    2001  to  Indenture  dated  as  of  November  1,  2000  from
                    Generating  Company  to The Bank of New  York,  as  Trustee,
                    relating to Generating  Company's 7.75% Senior Notes, Series
                    C due  2005  and  8.35%  Senior  Note,  Series  D  due  2010
                    (including  as exhibit the form of Exchange  Note) (File No.
                    333-56594, Exhibit 4.3).

       4.22         Third  Supplemental  Indenture  dated as of June 1,  2002 to
                    Indenture  dated as of  November  1,  2000  from  Generating
                    Company to The Bank of New York,  as  Trustee,  relating  to
                    Generating  Company's 7.95% Senior Notes,  Series E due 2032
                    (including  as  exhibit  the form of Note)  (June  30,  2002
                    Generating Company Form 10-Q, Exhibit 4.1).

       4.23         Fourth  Supplemental  Indenture dated as of January 15, 2003
                    to  Indenture  dated as of November 1, 2000 from  Generating
                    Company to The Bank of New York,  as  Trustee,  relating  to
                    Generating  Company's 7.95% Senior Notes,  Series F due 2032
                    (including as exhibit the form of Exchange Note) (Generating
                    Company 2002 Form 10-K, Exhibit 4.5).

       4.24         Indenture  of Ameren with The Bank of New York,  as Trustee,
                    relating to senior debt  securities  dated as of December 1,
                    2001  (Ameren's  Senior   Indenture)  (File  No.  333-81774,
                    Exhibit 4.5).

       4.25         Ameren company order relating to $150 million  Floating Rate
                    Notes due  December 12, 2003 issued  under  Ameren's  Senior
                    Indenture   (including   the  forms  of  notes)   (File  No.
                    333-81774, Exhibit 4.6).

       4.26         Ameren  company  order  relating to $100 million 5.70% Notes
                    due February 1, 2007 issued under Ameren's Senior  Indenture
                    (including the forms of notes) (File No. 333-81774,  Exhibit
                    4.7).

       4.27         Ameren  company order relating to $345 million Notes due May
                    15, 2007 issued under Ameren's Senior  Indenture  (including
                    the forms of notes and certificate of normal unit) (File No.
                    333-81774, Exhibit 4.8).

       4.28         Purchase  Contract  Agreement  dated  as of  March  1,  2002
                    between  Ameren  and  The  Bank  of New  York,  as  purchase
                    contract agent,  relating to the 13,800,000 9.75% Adjustable
                    Conversion-Rate   Equity  Security  Units  (Equity  Security
                    Units) (File No. 333-81774, Exhibit 4.15).

                                       25



     Exhibit No.                   Description
     -----------                   -----------

       4.29         Pledge Agreement dated as of March 1, 2002 among Ameren, The
                    Bank of New York, as purchase  contract  agent and BNY Trust
                    Company of Missouri,  as collateral  agent,  custodial agent
                    and securities intermediary, relating to the Equity Security
                    Units (File No. 333-81774, Exhibit 4.16).

       4.30         Indenture,  dated as of October 18,  1999,  between  Midwest
                    Energy,  Inc and The Bank of New  York,  as  Trustee;  First
                    Supplemental  Indenture,  dated  as  of  October  18,  1999,
                    between CILCORP Inc. and The Bank of New York (Designated in
                    registration  statement  Form  S-4  filed by  CILCORP,  Inc.
                    (CILCORP) on November 4, 1999, as exhibits 4.1 and 4.2).

       4.31         Indenture  of Mortgage  and Deed of Trust  between  Illinois
                    Power Company and Bankers Trust Company,  as Trustee,  dated
                    as of April 1, 1933, Supplemental Indenture between the same
                    parties  dated as of June 30, 1933,  Supplemental  Indenture
                    between the Company and Bankers Trust  Company,  as Trustee,
                    dated as of July 1, 1933 and Supplemental  Indenture between
                    the same parties dated as of January 1, 1935, securing First
                    Mortgage Bonds, and indentures supplemental to the foregoing
                    through  November 1, 1994.  (Designated in Registration  No.
                    2-1937 as Exhibit B-1, in Registration No. 2-2093 as Exhibit
                    B-1(a),  in Form 8-K for April 1940, File No.  1-2732-2,  as
                    Exhibit A, in Form 8-K for December 1949, File No. 1-2732-2,
                    as  Exhibit  A, in Form  8-K for  December  1951,  File  No.
                    1-2732,  as Exhibit  A, in Form 8-K for July 1957,  File No.
                    1-2732,  as Exhibit  A, in Form 8-K for July 1958,  File No.
                    1-2732,  as Exhibit A, in Form 8-K for March 1960,  File No.
                    1-2732,  as Exhibit A, in Form 8-K for September  1961, File
                    No. 1-2732,  as Exhibit B, in Form 8-K for March 1963,  File
                    No.  1-2732,  as Exhibit A, in Form 8-K for  February  1966,
                    File No.  1-2732,  as Exhibit A, in Form 8-K for March 1967,
                    File No. 1-2732,  as Exhibit A, in Form 8-K for August 1970,
                    File No.  1-2732,  as Exhibit  A, in Form 8-K for  September
                    1971,  File  No.  1-2732,  as  Exhibit  A, in  Form  8-K for
                    September 1972,  File No. 1-2732,  as Exhibit A, in Form 8-K
                    for April 1974,  File No.  1-2732,  as Exhibit 2(b), in Form
                    8-K for June 1974,  File No.  1-2732,  as Exhibit A, in Form
                    8-K for March 1975,  File No. 1-2732,  as Exhibit A, in Form
                    8-K for May 1976,  File No.  1-2732,  as  Exhibit A, in Form
                    10-Q for the quarter ended June 30, 1978,  File No.  1-2732,
                    as Exhibit 2, in Form 10-K for the year ended  December  31,
                    1982, File No. 1-2732,  as Exhibit (4)(b), in Form 8-K dated
                    January 30, 1992,  File No.  1-2732,  as Exhibit (4) in Form
                    8-K dated January 29, 1993, File No. 1-2732,  as Exhibit (4)
                    and in Form 8-K dated December 2, 1994, File No. 1-2732,  as
                    Exhibit (4).)

       10.1      *  Ameren's  Long-Term  Incentive Plan of 1998 (1998 Form 10-K,
                    Exhibit 10.1).

       10.2      *  Ameren's  Change of Control  Severance Plan (1998 Form 10-K,
                    Exhibit 10.2).

       10.3      *  Ameren's Deferred Compensation Plan for Members of the Board
                    of Directors (1998 Form 10-K, Exhibit 10.4).

       10.4      *  Ameren's  Deferred  Compensation  Plan  for  Members  of the
                    Ameren  Leadership  Team as amended and  restated  effective
                    January 1, 2001 (2000 Form 10-K, Exhibit 10.1).

       10.5      *  Ameren's Executive Incentive  Compensation  Program Elective
                    Deferral  Provisions  for  Members of the Ameren  Leadership
                    Team as amended and restated effective January 1, 2001 (2000
                    Form 10-K, Exhibit 10.2).

       10.6         Asset  Transfer  Agreement  between  Generating  Company and
                    AmerenCIPS (June 30, 2000 AmerenCIPS Form 10-Q, Exhibit 10).

       10.7         Amended Electric Power Supply Agreement  between  Generating
                    Company and AmerenEnergy  Marketing Company  (Marketing Co.)
                    (File No. 333-56594, Exhibit 10.2).

       10.8         2nd  Amended   Electric  Power  Supply   Agreement   between
                    Generating  Company and  Marketing  Co. (March 31, 2001 Form
                    10-Q, Exhibit 10.1).

       10.9         Electric Power Supply  Agreement  between  Marketing Co. and
                    AmerenCIPS (File No. 333-56594, Exhibit 10.3).

                                       26



     Exhibit No.                   Description
     -----------                   -----------

       10.10        Amended  Electric Power Supply Agreement  between  Marketing
                    Co. and AmerenCIPS (March 31, 2001 Form 10-Q, Exhibit 10.2).

       10.11        Power Sales  Agreement  between  Marketing  Co. and AmerenUE
                    (September 30, 2001  Generating  Company Form 10-Q,  Exhibit
                    10.1).

       10.12        Power Sales  Agreement  between  Marketing  Co. and AmerenUE
                    (March 31, 2002 Generating Company Form 10-Q, Exhibit 10.1).

       10.13        Amended Joint Dispatch  Agreement among Generating  Company,
                    AmerenCIPS and AmerenUE (File No. 333-56594, Exhibit 10.4).

       10.14        Lease  Agreement  dated as of December  1, 2002  between the
                    City of Bowling Green, Missouri, as Lessor, and AmerenUE, as
                    Lessee (AmerenUE 2002 Form 10-K, Exhibit 10.9).

       10.15        Trust  Indenture  dated as of December  1, 2002  between the
                    City of Bowling Green,  Missouri and Commerce Bank,  N.A. as
                    Trustee (AmerenUE 2002 Form 10-K, Exhibit 10.10).

       10.16        Bond  Purchase  Agreement  dated  as of  December  20,  2002
                    between the City of Bowling Green,  Missouri and AmerenUE as
                    purchaser (AmerenUE 2002 Form 10-K, Exhibit 10.11).

       10.17    **  Amended and Restated Appendix I ITC Agreement dated February
                    14, 2003 between the Midwest Independent Transmission System
                    Operator,   Inc.   (Midwest   ISO)   and   GridAmerica   LLC
                    (GridAmerica).

       10.18    **  Amended and Restated Limited  Liability Company Agreement of
                    GridAmerica dated February 14, 2003.

       10.19    **  Amended  and   Restated   Master   Agreement  by  and  among
                    GridAmerica,    GridAmerica   Holdings   Inc.,   GridAmerica
                    Companies and National Grid USA dated February 14, 2003.

       10.20    **  Amended  and  Restated  Operation  Agreement  by  and  among
                    AmerenUE,  AmerenCIPS,  American Transmission Systems, Inc.,
                    Northern  Indiana  Public  Service  Company and  GridAmerica
                    dated February 14, 2003.

       10.21     *  CILCO Executive  Deferral Plan. As amended  effective August
                    15, 1999 (CILCORP 1999 Form 10-K, Exhibit 10).

       10.22     *  CILCO Executive Deferral Plan II. As amended effective April
                    1, 1999 (CILCORP 1999 Form 10-K, Exhibit 10a).

       10.23     *  CILCO Benefit  Replacement Plan. As amended effective August
                    15, 1999 (CILCORP 1999 Form 10-K, Exhibit 10b).

       10.24     *  Retention  Agreement  between Central Illinois Light Company
                    (CILCO) and Scott A. Cisel dated  October 16, 2001  (CILCORP
                    2001 Form 10-K, Exhibit 10c).

       10.25     *  Bonus Agreements  dated January 21, 2003,  between CILCO and
                    Robert J. Sprowls, Scott A. Cisel, James L. Luckey, III, and
                    Thomas S. Romanowski (CILCORP 2002 Form 10-K, Exhibit 10d).

       10.26     *  CILCO Involuntary Severance Pay Plan effective July 16, 2001
                    (CILCORP 2001 Form 10-K, Exhibit 10e).

       10.27     *  CILCO Restructured  Executive Deferral Plan (approved August
                    15, 1999) (CILCORP 1999 Form 10-K, Exhibit 10e).

                                       27



     Exhibit No.                   Description
     -----------                   -----------

       12.1     **  Statement  of  Computation  of  Ratio of  Earnings  to Fixed
                    Charges and Preferred Stock Dividend Requirements.

       13.1     **  Those pages of the 2002 Annual Report incorporated herein by
                    reference.

       21.1     **  Subsidiaries of Ameren.

       23.1     **  Consent of Independent Accountants.

       24.1     **  Power of Attorney.

       99.1         Stipulation  and  Agreement  dated July 15, 2002 in Missouri
                    Public  Service  Commission  (as  No.  EC-2002-1   (earnings
                    complaint  case against  AmerenUE)  File Nos.  333-87506 and
                    333-87506-01, Exhibit 99.1).

       99.2     **  Certificate of Chief Executive  Officer  required by Section
                    906 of the Sarbanes-Oxley Act of 2002.

       99.3     **  Certificate of Chief Financial  Officer  required by Section
                    906    of     the     Sarbanes-Oxley     Act    of     2002.
       ----------------------------
        *Management compensatory plan or arrangement.
       **Filed herewith.


     Exhibits Available Upon Request
     -------------------------------

     The  following  instruments  defining  the  rights of  holders  of  certain
     unregistered  long-term debt of AmerenCIPS and AmerenUE have not been filed
     with the SEC but will be furnished upon request.

          Loan Agreement dated January 1, 1993,  between AmerenCIPS and Illinois
          Development   Finance  Authority  (IDFA)  in  connection  with  IDFA's
          $35,000,000, 6-3/8% Pollution Control Revenue Refunding Bonds (Central
          Illinois Public Service Company Project) 1993 Series A, due January 1,
          2028.

          Loan  Agreement  dated June 1, 1993,  between  AmerenCIPS  and IDFA in
          connection with IDFA's $17,500,000 Pollution Control Revenue Refunding
          Bonds,  1993  Series  B-1 due June 1, 2028 and  $17,500,000  Pollution
          Control Revenue Refunding Bonds, 1993 Series B-2 due June 1, 2028.

          Loan Agreement dated August 15, 1993,  between  AmerenCIPS and IDFA in
          connection with IDFA's $35,000,000 Pollution Control Revenue Refunding
          Bonds,  1993 Series C-1 due August 15, 2026 and $25,000,000  Pollution
          Control Revenue Refunding Bonds, 1993 Series C-2 due August 15, 2026.

          Loan  Agreement  dated March 1, 2000,  between  AmerenCIPS and IDFA in
          connection  with the  IDFA's  $51,100,000  Pollution  Control  Revenue
          Refunding Bonds (AmerenCIPS Project) Series 2000A due March 1, 2014.

          Loan  Agreement  dated March 1, 2000,  between  AmerenUE and the State
          Environmental  Improvement and Energy Resources Authority of the State
          of  Missouri  (EIERA)  in  connection  with the  EIERA's  $186,500,000
          Environmental  Improvement  Revenue Refunding Bonds (AmerenUE Project)
          ($63,500,000  Series 2000A,  $63,000,000 Series 2000B, and $60,000,000
          Series 2000C) due March 1, 2035.

Note:     Reports of Union  Electric  Company on Forms 8-K, 10-Q and 10-K are on
          file with the SEC under File Number 1-2967.

                                       28



          Reports of Central  Illinois Public Service Company on Forms 8-K, 10-Q
          and 10-K are on file with the SEC under File Number 1-3672.

          Reports of AmerenEnergy Generating Company on Forms 8-K, 10-Q and 10-K
          are on file with the SEC under File Number 333-56594.

          Reports of CILCORP  Inc. on Forms 8-K,  10-Q and 10-K are on file with
          the SEC under File Number 1-8946.

          Reports of Central  Illinois Light Company on Forms 8-K, 10-Q and 10-K
          are on file with the SEC under File Number 1-2732.

                                       29




                        REPORT OF INDEPENDENT ACCOUNTANTS
                         ON FINANCIAL STATEMENT SCHEDULE
                        ---------------------------------






To the Board of Directors
of Ameren Corporation:

Our audits of the consolidated  financial  statements  referred to in our report
dated February 13, 2003 appearing in the 2002 Annual Report to  Shareholders  of
Ameren  Corporation  (which report and  consolidated  financial  statements  are
incorporated  by reference in this Annual  Report on Form 10-K) also included an
audit of the financial  statement  schedule listed in Item 15(A)(2) of this Form
10-K. In our opinion,  this financial statement schedule presents fairly, in all
material  respects,  the  information set forth therein when read in conjunction
with the related consolidated financial statements.




/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP
St. Louis, Missouri
February 13, 2003


                                       30





                                                                       AMEREN CORPORATION
                                                         SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS
                                                      FOR THE YEARS ENDED DECEMBER 31, 2002, 2001 AND 2000



    Col. A.                            Col. B                      Col. C                             Col. D              Col. E
    ------                             ------                      ------                             ------              ------

                                                                  Additions
                                                       ---------------------------------
                                                          (1)                   (2)
                                     Balance at        Charged to                                                       Balance at
                                     beginning         costs and            Charged to                                    end of
   Description                       of period         expenses           other accounts             Deductions           period
   -----------                       ----------        ----------         --------------             ----------         ----------
                                                                                                       (Note)
                                                                                                            
Year ended December 31, 2002

Reserves deducted in the balance
 sheet from assets to which they
 apply:

   Allowance for doubtful accounts   $8,783,464        $19,993,000                                    $21,426,933       $7,349,531
                                     ==========        ===========                                    ===========       ==========




Year ended December 31, 2001

Reserves deducted in the balance
 sheet from assets to which they
 apply:

    Allowance for doubtful accounts  $8,028,034        $23,654,000                                    $22,898,570       $8,783,464
                                     ==========        ===========                                    ===========       ==========




Year ended December 31, 2000

Reserves deducted in the balance
 sheet from assets to which they
 apply:

    Allowance for doubtful accounts  $7,136,340        $11,540,000                                    $10,648,306       $8,028,034
                                     ==========        ===========                                    ===========       ==========


Note:  Uncollectible accounts charged off, less recoveries.

                                       31




                                   SIGNATURES

     Pursuant  to the  requirements  of  Section  13 or 15(d) of the  Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.

                                           AMEREN CORPORATION
                                              (Registrant)


Date:  March 31, 2003                      By     /s/ Charles W. Mueller
                                             -----------------------------------
                                                      Charles W. Mueller
                                            Chairman and Chief Executive Officer

     Pursuant to the  requirements of the Securities  Exchange Act of 1934, this
report  has  been  signed  below  by the  following  persons  on  behalf  of the
registrant and in the capacities and on the date indicated.

       Signature                    Title                              Date
       ---------                    -----                              ----

/s/ Charles W. Mueller      Chairman, Chief Executive             March 31, 2003
------------------------    Officer and Director
    Charles W. Mueller      (Principal Executive Officer)

/s/ Gary L. Rainwater       President and Chief Operating Officer March 31, 2003
------------------------
    Gary L. Rainwater

/s/ Warner L. Baxter        Senior Vice President, Finance        March 31, 2003
------------------------    (Principal Financial Officer)
    Warner L. Baxter

/s/ Martin J. Lyons         Vice President and Controller         March 31, 2003
------------------------    (Principal Accounting Officer)
    Martin J. Lyons

           *                Director                              March 31, 2003
------------------------
    William E. Cornelius

           *                Director                              March 31, 2003
------------------------
   Clifford L. Greenwalt

           *                Director                              March 31, 2003
------------------------
   Thomas A. Hays

           *                Director                              March 31, 2003
-------------------------
   Richard A. Liddy

           *                Director                              March 31, 2003
-------------------------
   Gordon R. Lohman

           *                Director                              March 31, 2003
-------------------------
   Richard A. Lumpkin

           *                Director                              March 31, 2003
-------------------------
   John Peters MacCarthy

           *                Director                              March 31, 2003
--------------------------
   Hanne M. Merriman

           *                Director                              March 31, 2003
---------------------------
   Paul L. Miller, Jr.

           *                Director                              March 31, 2003
---------------------------
   Harvey Saligman

           *                Director                              March 31, 2003
---------------------------
   James W. Wogsland


*By  /s/ Steven R. Sullivan                                       March 31, 2003
    ------------------------------------
         Steven R. Sullivan
          Attorney-in-Fact




                                       32



                                 CERTIFICATIONS



     I, Charles W. Mueller, certify that:



     1.   I have reviewed this annual report on Form 10-K of Ameren Corporation;

     2.   Based on my knowledge,  this annual report does not contain any untrue
          statement  of a  material  fact  or  omit to  state  a  material  fact
          necessary to make the statements  made, in light of the  circumstances
          under which such  statements were made, not misleading with respect to
          the period covered by this annual report;

     3.   Based on my knowledge,  the financial statements,  and other financial
          information  included in this  annual  report,  fairly  present in all
          material respects the financial  condition,  results of operations and
          cash flows of the registrant as of, and for, the periods  presented in
          this annual report;

     4.   The registrant's  other  certifying  officer and I are responsible for
          establishing  and maintaining  disclosure  controls and procedures (as
          defined in Exchange  Act Rules  13a-14 and 15d-14) for the  registrant
          and have:

          a)   designed such  disclosure  controls and procedures to ensure that
               material  information  relating to the registrant,  including its
               consolidated  subsidiaries,  is made known to us by others within
               those  entities,  particularly  during  the  period in which this
               annual report is being prepared;

          b)   evaluated  the  effectiveness  of  the  registrant's   disclosure
               controls and  procedures as of a date within 90 days prior to the
               filing date of this annual report (the Evaluation Date); and

          c)   presented  in  this  annual  report  our  conclusions  about  the
               effectiveness of the disclosure  controls and procedures based on
               our evaluation as of the Evaluation Date;

     5.   The registrant's other certifying officer and I have disclosed,  based
          on our most recent  evaluation,  to the registrant's  auditors and the
          audit  committee  of  registrant's  board  of  directors  (or  persons
          performing the equivalent functions):

          a)   all  significant  deficiencies  in the  design  or  operation  of
               internal  controls which could adversely  affect the registrant's
               ability to record,  process,  summarize and report financial data
               and have  identified for the  registrant's  auditors any material
               weaknesses in internal controls; and

          b)   any fraud,  whether or not material,  that involves management or
               other employees who have a significant  role in the  registrant's
               internal controls; and

     6.   The registrant's other certifying officer and I have indicated in this
          annual  report  whether  there were  significant  changes in  internal
          controls or in other factors that could significantly  affect internal
          controls  subsequent  to the  date  of  our  most  recent  evaluation,
          including   any   corrective   actions  with  regard  to   significant
          deficiencies and material weaknesses.



Date:  March 31, 2003                        /s/ Charles W. Mueller
                                             -----------------------------------
                                             Charles W. Mueller
                                             Chief Executive Officer


                                       33





                           CERTIFICATIONS (CONTINUED)



     I, Warner L. Baxter, certify that:



     1.   I have reviewed this annual report on Form 10-K of Ameren Corporation;

     2.   Based on my knowledge,  this annual report does not contain any untrue
          statement  of a  material  fact  or  omit to  state  a  material  fact
          necessary to make the statements  made, in light of the  circumstances
          under which such  statements were made, not misleading with respect to
          the period covered by this annual report;

     3.   Based on my knowledge,  the financial statements,  and other financial
          information  included in this  annual  report,  fairly  present in all
          material respects the financial  condition,  results of operations and
          cash flows of the registrant as of, and for, the periods  presented in
          this annual report;

     4.   The registrant's  other  certifying  officer and I are responsible for
          establishing  and maintaining  disclosure  controls and procedures (as
          defined in Exchange  Act Rules  13a-14 and 15d-14) for the  registrant
          and have:

          a)   designed such  disclosure  controls and procedures to ensure that
               material  information  relating to the registrant,  including its
               consolidated  subsidiaries,  is made known to us by others within
               those  entities,  particularly  during  the  period in which this
               annual report is being prepared;

          b)   evaluated  the  effectiveness  of  the  registrant's   disclosure
               controls and  procedures as of a date within 90 days prior to the
               filing date of this annual report (the Evaluation Date); and

          c)   presented  in  this  annual  report  our  conclusions  about  the
               effectiveness of the disclosure  controls and procedures based on
               our evaluation as of the Evaluation Date;

     5.   The registrant's other certifying officer and I have disclosed,  based
          on our most recent  evaluation,  to the registrant's  auditors and the
          audit  committee  of  registrant's  board  of  directors  (or  persons
          performing the equivalent functions):

          a)   all  significant  deficiencies  in the  design  or  operation  of
               internal  controls which could adversely  affect the registrant's
               ability to record,  process,  summarize and report financial data
               and have  identified for the  registrant's  auditors any material
               weaknesses in internal controls; and

          b)   any fraud,  whether or not material,  that involves management or
               other employees who have a significant  role in the  registrant's
               internal controls; and

     6.   The registrant's other certifying officer and I have indicated in this
          annual  report  whether  there were  significant  changes in  internal
          controls or in other factors that could significantly  affect internal
          controls  subsequent  to the  date  of  our  most  recent  evaluation,
          including   any   corrective   actions  with  regard  to   significant
          deficiencies and material weaknesses.



Date:  March 31, 2003                        /s/ Warner L. Baxter
                                             -----------------------------------
                                             Warner L. Baxter
                                             Chief Financial Officer

                                       34



                                  EXHIBIT INDEX


     Exhibit No.                   Description
     -----------                   -----------

       2.1          Stock purchase agreement, dated as of April 28, 2002, by and
                    between The AES Corporation (AES) and Ameren (March 31, 2002
                    Form 10-Q, Exhibit 2.1).

       2.2          Membership  Interest Purchase  Agreement,  dated as of April
                    28, 2002, by and between AES and Ameren (March 31, 2002 Form
                    10-Q, Exhibit 2.2).

       3.1(i)       Restated  Articles  of  Incorporation  of  Ameren  (File No.
                    33-64165, Annex F).

       3.2(i)       Certificate  of Amendment to Ameren's  Restated  Articles of
                    Incorporation filed with the Secretary of State of the State
                    of Missouri on  December  14, 1998 (1998 Form 10-K,  Exhibit
                    3(i)).

       3.3(ii)      By-Laws of Ameren as amended to December 31, 1997 (1997 Form
                    10-K, Exhibit 3(ii)).

       4.1          Indenture  of Mortgage  and Deed of Trust of AmerenUE  dated
                    June 15, 1937 (AmerenUE  Mortgage),  as amended May 1, 1941,
                    and Second  Supplemental  Indenture  dated May 1, 1941 (File
                    No. 2-4940, Exhibit B-1).

       4.2          Supplemental Indentures to the AmerenUE Mortgage



                    Dated as of                   File Reference                            Exhibit No.
                    -----------                   --------------                            -----------
                                                                                   
                    April 1, 1971          AmerenUE Form 8-K, April 1971                         6
                    February 1, 1974       AmerenUE Form 8-K, February 1974                      3
                    July 7, 1980           2-69821                                             4.6
                    December 1, 1991       33-45008                                            4.4
                    December 4, 1991       33-45008                                            4.5
                    January 1, 1992        AmerenUE Form 10-K, 1991                            4.6
                    October 1, 1992        AmerenUE Form 10-K, 1992                            4.6
                    December 1, 1992       AmerenUE Form 10-K, 1992                            4.7
                    February 1, 1993       AmerenUE Form 10-K, 1992                            4.8
                    May 1, 1993            AmerenUE Form 10-K, 1993                            4.6
                    August 1, 1993         AmerenUE Form 10-K, 1993                            4.7
                    October 1, 1993        AmerenUE Form 10-K, 1993                            4.8
                    January 1, 1994        AmerenUE Form 10-K, 1993                            4.9
                    February 1, 2000       AmerenUE Form 10-K, 2000                            4.1
                    August 15, 2002        AmerenUE Form 8-K, August 22, 2002                  4.3
                    March 5, 2003          AmerenUE Form 8-K, March 10, 2003                   4.4


       4.3          Indenture (for unsecured  subordinated  debt  securities) of
                    AmerenUE  dated as of December 1, 1996  (AmerenUE  1996 Form
                    10-K, Exhibit 4.36).

       4.4          Loan  Agreement  dated as of  December  1, 1991  between the
                    State   Environmental   Improvement  and  Energy   Resources
                    Authority  and AmerenUE,  together  with  Indenture of Trust
                    dated as of December 1, 1991 between the  Authority  and UMB
                    Bank,  N.A. as successor  trustee to Mercantile  Bank of St.
                    Louis, N.A. (AmerenUE 1992 Form 10-K, Exhibit 4.37).

       4.5          Loan  Agreement  dated as of December  1, 1992,  between the
                    State   Environmental   Improvement  and  Energy   Resources
                    Authority  and AmerenUE,  together  with  Indenture of Trust
                    dated as of December 1, 1992 between the  Authority  and UMB
                    Bank,  N.A. as successor  trustee to Mercantile  Bank of St.
                    Louis, N.A. (AmerenUE 1992 Form 10-K, Exhibit 4.38).

       4.6          Fuel Lease dated as of February 24, 1981  between  AmerenUE,
                    as lessee,  and Gateway Fuel  Company,  as lessor,  covering
                    nuclear fuel (AmerenUE 1980 Form 10-K, Exhibit 10.20).

                                       35



     Exhibit No.                   Description
     -----------                   -----------
       4.7          Amendments to Fuel Lease dated as of May 8, 1984 and October
                    15, 1984,  respectively,  between AmerenUE,  as lessee,  and
                    Gateway Fuel Company, as lessor, covering nuclear fuel (File
                    No. 2-96198, Exhibit 4.28).

       4.8          Amendment to Fuel Lease dated as of October 15, 1986 between
                    AmerenUE,  as lessee,  and Gateway Fuel Company,  as lessor,
                    covering  nuclear  fuel  (AmerenUE  September  30, 1986 Form
                    10-Q, Exhibit 4.3).

       4.9          Series  1998A Loan  Agreement  dated as of September 1, 1998
                    between  The  State  Environmental  Improvement  and  Energy
                    Resources  Authority  of the State of Missouri  and AmerenUE
                    (AmerenUE September 30, 1998 Form 10-Q, Exhibit 4.28).

       4.10         Series  1998B Loan  Agreement  dated as of September 1, 1998
                    between  The  State  Environmental  Improvement  and  Energy
                    Resources  Authority  of the State of Missouri  and AmerenUE
                    (AmerenUE September 30, 1998 Form 10-Q, Exhibit 4.29).

       4.11         Series  1998C Loan  Agreement  dated as of September 1, 1998
                    between  The  State  Environmental  Improvement  and  Energy
                    Resources  Authority  of the State of Missouri  and AmerenUE
                    (AmerenUE September 30, 1998 Form 10-Q, Exhibit 4.30).

       4.12         Indenture  dated as of August 15, 2002 from  AmerenUE to The
                    Bank of New York,  as Trustee,  relating  to senior  secured
                    debt securities  (including the forms of senior secured debt
                    securities as exhibits) (Ameren UE Form 8-K dated August 22,
                    2002, Exhibit 4.1).

       4.13         AmerenUE  Company  order dated August 22, 2002  establishing
                    the 5.25% Senior  Secured Notes due 2012  (AmerenUE Form 8-K
                    dated August 22, 2002, Exhibit 4.2).

       4.14         AmerenUE Company order dated March 10, 2003 establishing the
                    5.50% Senior Secured Notes due 2034 (AmerenUE Form 8-K dated
                    March 10, 2003, Exhibit 4.2).

       4.15         Indenture  of  Mortgage  or Deed of Trust  dated  October 1,
                    1941,  from Central  Illinois  Public Service  Company d/b/a
                    AmerenCIPS  (AmerenCIPS)  to Continental  Illinois  National
                    Bank and Trust  Company of Chicago and Edmond B. Stofft,  as
                    Trustees (U.S.  Bank Trust National  Association and Patrick
                    J. Crowley are  successor  Trustees.)  (Exhibit 2.01 in File
                    No. 2-60232).

       4.16         Supplemental  Indentures  dated,  respectively  September 1,
                    1947, January 1, 1949, February 1, 1952,  September 1, 1952,
                    June 1,  1954,  February  1, 1958,  January 1, 1959,  May 1,
                    1963, May 1, 1964, June 1, 1965, May 1, 1967, April 1, 1970,
                    April 1, 1971,  September 1, 1971, May 1, 1972,  December 1,
                    1973,  March  1,  1974,  April 1,  1975,  October  1,  1976,
                    November 1, 1976, October 1, 1978, August 1, 1979,  February
                    1, 1980,  February  1,  1986,  May 15,  1992,  July 1, 1992,
                    September 15, 1992,  April 1, 1993, June 1, 1995,  March 15,
                    1997,  June 1,  1997,  December  1,  1998 and  June 1,  2001
                    between  AmerenCIPS  and the Trustees under the Indenture of
                    Mortgage or Deed of Trust  referred to above as Exhibit 4.14
                    (Amended  Exhibit 7(b) in File No.  2-7341;  Second  Amended
                    Exhibit 7.03 in File No. 2-7795; Second Amended Exhibit 4.07
                    in File No. 2-9353; Amended Exhibit 4.05 in File No. 2-9802;
                    Amended  Exhibit 4.02 in File No.  2-10944;  Amended Exhibit
                    2.02 in File No.  2-13866;  Amended Exhibit 2.02 in File No.
                    2-14656;  Amended Exhibit 2.02 in File  No.2-21345;  Amended
                    Exhibit 2.02 in File No.  2-22326;  Amended  Exhibit 2.02 in
                    File No. 2-23569;  Amended Exhibit 2.02 in File No. 2-26284;
                    Amended  Exhibit 2.02 in File No.  2-36388;  Amended Exhibit
                    2.02 in File No.  2-39587;  Amended Exhibit 2.02 in File No.
                    2-41468;  Amended Exhibit 2.02 in File No. 2-43912;  Exhibit
                    2.03 in File No.  2-60232;  Amended Exhibit 2.02 in File No.
                    2-50146;  Amended Exhibit 2.02 in File No.  2-52886;  Second
                    Amended  Exhibit 2.04 in File No.  2-57141;  Amended Exhibit
                    2.04 in File No.  2-57557;  Amended Exhibit 2.06 in File No.
                    2-62564;  Exhibit  2.02(a)  in  File  No.  2-65914;  Amended
                    Exhibit  2.02(a) in File No.  2-66380;  and Amended  Exhibit
                    4.02 in File No.  33-3188;  Exhibit 4.02 to AmerenCIPS  Form
                    8-K dated May 15, 1992;  Exhibit 4.02 to AmerenCIPS Form 8-K
                    dated  July 1, 1992;  Exhibit  4.02 to  AmerenCIPS  Form 8-K
                    dated  September 15, 1992;  Exhibit 4.02 to AmerenCIPS  Form
                    8-K dated March 30, 1993;  Exhibit

                                       36



                    4.03 to AmerenCIPS Form 8-K dated June 5, 1995; Exhibit 4.03
                    to AmerenCIPS Form 8-K dated March 15, 1997; Exhibit 4.03 to
                    AmerenCIPS Form 8-K dated June 1, 1997;  Exhibit 4.2 in File
                    No. 333-59438;  Exhibit 4.1 to June 30, 2001 AmerenCIPS Form
                    10-Q.)

     Exhibit No.                   Description
     -----------                   -----------

       4.17         Agreement,  dated as of October 9, 1998,  between Ameren and
                    EquiServe Trust Company, N.A. (as successor to First Chicago
                    Trust Company of New York), as Rights Agent,  which includes
                    the form of  Certificate  of  Designation  of the  Preferred
                    Shares  as  Exhibit  A, the form of  Rights  Certificate  as
                    Exhibit B and the  Summary  of Rights as  Exhibit C (October
                    14, 1998 Form 8-K, Exhibit 4).

       4.18         Indenture  dated as of December 1, 1998 from  AmerenCIPS  to
                    The Bank of New York,  as Trustee,  relating to  AmerenCIPS'
                    Senior  Notes,  5.375% due 2008 and 6.125% due 2028 (Exhibit
                    4.4, in File No. 333-59438).

       4.19         Indenture  dated as of  November  1, 2000 from  AmerenEnergy
                    Generating Company  (Generating  Company) to The Bank of New
                    York,  as Trustee,  relating to the issuance of senior notes
                    (File No. 333-56594, Exhibit 4.1).

       4.20         First Supplemental Indenture dated as of November 1, 2000 to
                    Indenture  dated as of  November  1,  2000  from  Generating
                    Company to The Bank of New York,  as  Trustee,  relating  to
                    Generating  Company's 7.75% Senior Notes,  Series A due 2005
                    and  8.35%  Senior  Notes,  Series  B  due  2010  (File  No.
                    333-56594, Exhibit 4.2).

       4.21         Form of Second  Supplemental  Indenture dated as of June 12,
                    2001  to  Indenture  dated  as  of  November  1,  2000  from
                    Generating  Company  to The Bank of New  York,  as  Trustee,
                    relating to Generating  Company's 7.75% Senior Notes, Series
                    C due  2005  and  8.35%  Senior  Note,  Series  D  due  2010
                    (including  as exhibit the form of Exchange  Note) (File No.
                    333-56594, Exhibit 4.3).

       4.22         Third  Supplemental  Indenture  dated as of June 1,  2002 to
                    Indenture  dated as of  November  1,  2000  from  Generating
                    Company to The Bank of New York,  as  Trustee,  relating  to
                    Generating  Company's 7.95% Senior Notes,  Series E due 2032
                    (including  as  exhibit  the form of Note)  (June  30,  2002
                    Generating Company Form 10-Q, Exhibit 4.1).

       4.23         Fourth  Supplemental  Indenture dated as of January 15, 2003
                    to  Indenture  dated as of November 1, 2000 from  Generating
                    Company to The Bank of New York,  as  Trustee,  relating  to
                    Generating  Company's 7.95% Senior Notes,  Series F due 2032
                    (including as exhibit the form of Exchange Note) (Generating
                    Company 2002 Form 10-K, Exhibit 4.5).

       4.24         Indenture  of Ameren with The Bank of New York,  as Trustee,
                    relating to senior debt  securities  dated as of December 1,
                    2001  (Ameren's  Senior   Indenture)  (File  No.  333-81774,
                    Exhibit 4.5).

       4.25         Ameren company order relating to $150 million  Floating Rate
                    Notes due  December 12, 2003 issued  under  Ameren's  Senior
                    Indenture   (including   the  forms  of  notes)   (File  No.
                    333-81774, Exhibit 4.6).

       4.26         Ameren  company  order  relating to $100 million 5.70% Notes
                    due February 1, 2007 issued under Ameren's Senior  Indenture
                    (including the forms of notes) (File No. 333-81774,  Exhibit
                    4.7).

       4.27         Ameren  company order relating to $345 million Notes due May
                    15, 2007 issued under Ameren's Senior  Indenture  (including
                    the forms of notes and certificate of normal unit) (File No.
                    333-81774, Exhibit 4.8).

       4.28         Purchase  Contract  Agreement  dated  as of  March  1,  2002
                    between  Ameren  and  The  Bank  of New  York,  as  purchase
                    contract agent,  relating to the 13,800,000 9.75% Adjustable
                    Conversion-Rate   Equity  Security  Units  (Equity  Security
                    Units) (File No. 333-81774, Exhibit 4.15).

                                       37



     Exhibit No.                   Description
     -----------                   -----------

       4.29         Pledge Agreement dated as of March 1, 2002 among Ameren, The
                    Bank of New York, as purchase  contract  agent and BNY Trust
                    Company of Missouri,  as collateral  agent,  custodial agent
                    and securities intermediary, relating to the Equity Security
                    Units (File No. 333-81774, Exhibit 4.16).

       4.30         Indenture,  dated as of October 18,  1999,  between  Midwest
                    Energy,  Inc and The Bank of New  York,  as  Trustee;  First
                    Supplemental  Indenture,  dated  as  of  October  18,  1999,
                    between CILCORP Inc. and The Bank of New York (Designated in
                    registration  statement  Form  S-4  filed by  CILCORP,  Inc.
                    (CILCORP) on November 4, 1999, as exhibits 4.1 and 4.2).

       4.31         Indenture  of Mortgage  and Deed of Trust  between  Illinois
                    Power Company and Bankers Trust Company,  as Trustee,  dated
                    as of April 1, 1933, Supplemental Indenture between the same
                    parties  dated as of June 30, 1933,  Supplemental  Indenture
                    between the Company and Bankers Trust  Company,  as Trustee,
                    dated as of July 1, 1933 and Supplemental  Indenture between
                    the same parties dated as of January 1, 1935, securing First
                    Mortgage Bonds, and indentures supplemental to the foregoing
                    through  November 1, 1994.  (Designated in Registration  No.
                    2-1937 as Exhibit B-1, in Registration No. 2-2093 as Exhibit
                    B-1(a),  in Form 8-K for April 1940, File No.  1-2732-2,  as
                    Exhibit A, in Form 8-K for December 1949, File No. 1-2732-2,
                    as  Exhibit  A, in Form  8-K for  December  1951,  File  No.
                    1-2732,  as Exhibit  A, in Form 8-K for July 1957,  File No.
                    1-2732,  as Exhibit  A, in Form 8-K for July 1958,  File No.
                    1-2732,  as Exhibit A, in Form 8-K for March 1960,  File No.
                    1-2732,  as Exhibit A, in Form 8-K for September  1961, File
                    No. 1-2732,  as Exhibit B, in Form 8-K for March 1963,  File
                    No.  1-2732,  as Exhibit A, in Form 8-K for  February  1966,
                    File No.  1-2732,  as Exhibit A, in Form 8-K for March 1967,
                    File No. 1-2732,  as Exhibit A, in Form 8-K for August 1970,
                    File No.  1-2732,  as Exhibit  A, in Form 8-K for  September
                    1971,  File  No.  1-2732,  as  Exhibit  A, in  Form  8-K for
                    September 1972,  File No. 1-2732,  as Exhibit A, in Form 8-K
                    for April 1974,  File No.  1-2732,  as Exhibit 2(b), in Form
                    8-K for June 1974,  File No.  1-2732,  as Exhibit A, in Form
                    8-K for March 1975,  File No. 1-2732,  as Exhibit A, in Form
                    8-K for May 1976,  File No.  1-2732,  as  Exhibit A, in Form
                    10-Q for the quarter ended June 30, 1978,  File No.  1-2732,
                    as Exhibit 2, in Form 10-K for the year ended  December  31,
                    1982, File No. 1-2732,  as Exhibit (4)(b), in Form 8-K dated
                    January 30, 1992,  File No.  1-2732,  as Exhibit (4) in Form
                    8-K dated January 29, 1993, File No. 1-2732,  as Exhibit (4)
                    and in Form 8-K dated December 2, 1994, File No. 1-2732,  as
                    Exhibit (4).)

       10.1      *  Ameren's  Long-Term  Incentive Plan of 1998 (1998 Form 10-K,
                    Exhibit 10.1).

       10.2      *  Ameren's  Change of Control  Severance Plan (1998 Form 10-K,
                    Exhibit 10.2).

       10.3      *  Ameren's Deferred Compensation Plan for Members of the Board
                    of Directors (1998 Form 10-K, Exhibit 10.4).

       10.4      *  Ameren's  Deferred  Compensation  Plan  for  Members  of the
                    Ameren  Leadership  Team as amended and  restated  effective
                    January 1, 2001 (2000 Form 10-K, Exhibit 10.1).

       10.5      *  Ameren's Executive Incentive  Compensation  Program Elective
                    Deferral  Provisions  for  Members of the Ameren  Leadership
                    Team as amended and restated effective January 1, 2001 (2000
                    Form 10-K, Exhibit 10.2).

       10.6         Asset  Transfer  Agreement  between  Generating  Company and
                    AmerenCIPS (June 30, 2000 AmerenCIPS Form 10-Q, Exhibit 10).

       10.7         Amended Electric Power Supply Agreement  between  Generating
                    Company and AmerenEnergy  Marketing Company  (Marketing Co.)
                    (File No. 333-56594, Exhibit 10.2).

       10.8         2nd  Amended   Electric  Power  Supply   Agreement   between
                    Generating  Company and  Marketing  Co. (March 31, 2001 Form
                    10-Q, Exhibit 10.1).

       10.9         Electric Power Supply  Agreement  between  Marketing Co. and
                    AmerenCIPS (File No. 333-56594, Exhibit 10.3).

                                       38



     Exhibit No.                   Description
     -----------                   -----------

       10.10        Amended  Electric Power Supply Agreement  between  Marketing
                    Co. and AmerenCIPS (March 31, 2001 Form 10-Q, Exhibit 10.2).

       10.11        Power Sales  Agreement  between  Marketing  Co. and AmerenUE
                    (September 30, 2001  Generating  Company Form 10-Q,  Exhibit
                    10.1).

       10.12        Power Sales  Agreement  between  Marketing  Co. and AmerenUE
                    (March 31, 2002 Generating Company Form 10-Q, Exhibit 10.1).

       10.13        Amended Joint Dispatch  Agreement among Generating  Company,
                    AmerenCIPS and AmerenUE (File No. 333-56594, Exhibit 10.4).

       10.14        Lease  Agreement  dated as of December  1, 2002  between the
                    City of Bowling Green, Missouri, as Lessor, and AmerenUE, as
                    Lessee (AmerenUE 2002 Form 10-K, Exhibit 10.9).

       10.15        Trust  Indenture  dated as of December  1, 2002  between the
                    City of Bowling Green,  Missouri and Commerce Bank,  N.A. as
                    Trustee (AmerenUE 2002 Form 10-K, Exhibit 10.10).

       10.16        Bond  Purchase  Agreement  dated  as of  December  20,  2002
                    between the City of Bowling Green,  Missouri and AmerenUE as
                    purchaser (AmerenUE 2002 Form 10-K, Exhibit 10.11).

       10.17    **  Amended and Restated Appendix I ITC Agreement dated February
                    14, 2003 between the Midwest Independent Transmission System
                    Operator,   Inc.   (Midwest   ISO)   and   GridAmerica   LLC
                    (GridAmerica).

       10.18    **  Amended and Restated Limited  Liability Company Agreement of
                    GridAmerica dated February 14, 2003.

       10.19    **  Amended  and   Restated   Master   Agreement  by  and  among
                    GridAmerica,    GridAmerica   Holdings   Inc.,   GridAmerica
                    Companies and National Grid USA dated February 14, 2003.

       10.20    **  Amended  and  Restated  Operation  Agreement  by  and  among
                    AmerenUE,  AmerenCIPS,  American Transmission Systems, Inc.,
                    Northern  Indiana  Public  Service  Company and  GridAmerica
                    dated February 14, 2003.

       10.21     *  CILCO Executive  Deferral Plan. As amended  effective August
                    15, 1999 (CILCORP 1999 Form 10-K, Exhibit 10).

       10.22     *  CILCO Executive Deferral Plan II. As amended effective April
                    1, 1999 (CILCORP 1999 Form 10-K, Exhibit 10a).

       10.23     *  CILCO Benefit  Replacement Plan. As amended effective August
                    15, 1999 (CILCORP 1999 Form 10-K, Exhibit 10b).

       10.24     *  Retention  Agreement  between Central Illinois Light Company
                    (CILCO) and Scott A. Cisel dated  October 16, 2001  (CILCORP
                    2001 Form 10-K, Exhibit 10c).

       10.25     *  Bonus Agreements  dated January 21, 2003,  between CILCO and
                    Robert J. Sprowls, Scott A. Cisel, James L. Luckey, III, and
                    Thomas S. Romanowski (CILCORP 2002 Form 10-K, Exhibit 10d).

       10.26     *  CILCO Involuntary Severance Pay Plan effective July 16, 2001
                    (CILCORP 2001 Form 10-K, Exhibit 10e).

       10.27     *  CILCO Restructured  Executive Deferral Plan (approved August
                    15, 1999) (CILCORP 1999 Form 10-K, Exhibit 10e).

                                       39



     Exhibit No.                   Description
     -----------                   -----------

       12.2     **  Statement  of  Computation  of  Ratio of  Earnings  to Fixed
                    Charges and Preferred Stock Dividend Requirements.

       13.2     **  Those pages of the 2002 Annual Report incorporated herein by
                    reference.

       21.2     **  Subsidiaries of Ameren.

       23.2     **  Consent of Independent Accountants.

       24.2     **  Power of Attorney.

       99.1         Stipulation  and  Agreement  dated July 15, 2002 in Missouri
                    Public  Service  Commission  (as  No.  EC-2002-1   (earnings
                    complaint  case against  AmerenUE)  File Nos.  333-87506 and
                    333-87506-01, Exhibit 99.1).

       99.2     **  Certificate of Chief Executive  Officer  required by Section
                    906 of the Sarbanes-Oxley Act of 2002.

       99.3     **  Certificate of Chief Financial  Officer  required by Section
                    906    of     the     Sarbanes-Oxley     Act    of     2002.
       ----------------------------
        *Management compensatory plan or arrangement.
       **Filed herewith.

                                       40