Standard&Poor's Ratings Services has raised its rating on Tacoma, Wash.'s electric system revenue bonds outstanding to 'AA' from 'AA-'. At the same time, Standard&Poor's assigned its 'AA' rating to Tacoma's series 2010A, 2010B, and 2010C electric system revenue bonds. The outlook is stable. The utility expects to sell the 2010B bonds as direct-subsidy Build America Bonds (BABs), and the 2010C bonds as Clean Renewable Energy Bonds (CREBs). Tacoma has pledged its net electric system revenues to pay all principal and interest due on the bonds. The upgrade reflects our opinion of Tacoma's sustained strong financial condition. Fixed charged coverage at 1.6x or higher during fiscals 2006-2009, and unrestricted cash and investments of more than 300 days'