Nov 2 - As we previously announced, Standard & Poor's Ratings Services on Nov. 1, 2012, assigned its 'BBB-' issue rating to the proposed $475 million, 30-year senior unsecured notes issuance by El Paso Pipeline Partners Operating Co. LLC, which is guaranteed by El Paso Pipeline Partners L.P. (BBB-/Stable/--). The company said it will use the proceeds to repay borrowings under its existing revolving credit facility. Key credit ratios remain in line with our expectations. As of Sept. 30, 2012, Ho