LONDON (Standard&Poor's) March 17, 2009--Standard&Poor's Ratings Services said today that it assigned its insured 'A' long-term debt rating to the £192.65 million senior secured bonds (including £30 million of variation bonds yet to be issued) due 2043 of U.K.-based special purpose vehicle (SPV) BY Chelmer PLC (the Issuer or ProjectCo). The outlook on the insured rating is negative. The insured rating reflects the unconditional and irrevocable guarantee provided by Ambac Assurance U.K. Ltd. (Ambac; A/Negative/--) of payment of scheduled interest and principal on the bonds. At the same time, Standard&Poor's assigned its underlying 'BBB' long-term debt rating to the bonds, reflecting a composite of credit factors outlined below. The outlook on the underlying rating