Corporate Office Properties Trust (COPT or the Company) (NYSE: OFC) announced that in connection with the March 2010 private offering by COPT’s operating partnership, Corporate Office Properties, L.P. (COPLP), of 4.25% exchangeable notes (Notes), COPT plans to file a Registration Statement on Form S-3 with the Securities and Exchange Commission (SEC) in satisfaction of certain registration rights granted to the holders of the Notes. When filed, the new Registration Statement will replace the Registration Statement on Form S-3 filed with the SEC on April 13, 2010, which expires on April 13, 2013.

Once filed, the new Registration Statement will be effective immediately, and will be available for use by the holders of the outstanding Notes to resell the Notes. The holders of the Notes are not obligated to resell any of the Notes, and COPT will not receive any proceeds from any resales of the Notes.

COPT plans to file the new Registration Statement relating to the Notes with the SEC on or around April 8, 2013. This press release shall not constitute an offer to sell or a solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or jurisdiction.

Company Information:

COPT is an office REIT that focuses primarily on serving the specialized requirements of U.S. Government agencies and defense contractors, most of whom are engaged in defense information technology and national security-related activities. The Company generally acquires, develops, manages and leases office and data center properties concentrated in large office parks primarily located near knowledge-based government demand drivers and/or in targeted markets or submarkets in the Greater Washington, DC/Baltimore region. As of December 31, 2012, the Company’s consolidated portfolio consisted of 208 office properties totaling 18.8 million rentable square feet. COPT is an S&P MidCap 400 company and more information can be found at www.copt.com.

Forward-Looking Information:

This press release may contain “forward-looking” statements, as defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, that are based on the Company’s current expectations, estimates and projections about future events and financial trends affecting the Company. Forward-looking statements can be identified by the use of words such as “may,” “will,” “should,” “could,” “believe,” “anticipate,” “expect,” “estimate,” “plan” or other comparable terminology. Forward-looking statements are inherently subject to risks and uncertainties, many of which the Company cannot predict with accuracy and some of which the Company might not even anticipate. Accordingly, the Company can give no assurance that these expectations, estimates and projections will be achieved. Future events and actual results may differ materially from those discussed in the forward-looking statements.

Important factors that may affect these expectations, estimates, and projections include, but are not limited to:

• general economic and business conditions, which will, among other things, affect office property and data center demand and rents, tenant creditworthiness, interest rates, financing availability and property values;
• adverse changes in the real estate markets including, among other things, increased competition with other companies;
• governmental actions and initiatives, including risks associated with the impact of a government shutdown or budgetary reductions or impasses, such as a reduction in rental revenues, non-renewal of leases, and/or a curtailment of demand for additional space by strategic tenants;
• the Company’s ability to sell properties included in its Strategic Reallocation Plan;
• the Company’s ability to borrow on favorable terms;
• risks of real estate acquisition and development activities, including, among other things, risks that development projects may not be completed on schedule, that tenants may not take occupancy or pay rent or that development or operating costs may be greater than anticipated;
• risks of investing through joint venture structures, including risks that the Company’s joint venture partners may not fulfill their financial obligations as investors or may take actions that are inconsistent with the Company’s objectives;
• changes in the Company’s plans or views of market economic conditions or failure to obtain development rights, any of which could result in recognition of impairment losses;
• the Company’s ability to satisfy and operate effectively under Federal income tax rules relating to real estate investment trusts and partnerships;
• the Company's ability to achieve projected results;
• the dilutive effect of issuing additional common shares; and
• environmental requirements.

The Company undertakes no obligation to update or supplement any forward-looking statements. For further information, please refer to the Company’s filings with the Securities and Exchange Commission, particularly the section entitled “Risk Factors” in Item 1A of the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.