Standard&Poor's Rating Services has affirmed its 'BBB+' rating on Philadelphia, Pa.'s gas works revenue bonds, issued under its 1975 (closed senior lien) and 1998 ordinances (subordinate working lien). The outlook is stable. At the same time, Standard&Poor's affirmed its 'AAA/A-1+' and 'AA+/A-1' ratings on certain series of bonds, reflecting application of Standard&Poor's joint support criteria. The rating reflects our view of the following credit weaknesses: Weak service area demographics, which contribute to above average rates, historically exposing the utility to collection difficulties during periods of high gas costs or below-average temperatures; Mutual interdependence with the City of Philadelphia (general obligation rating: BBB+/Positive), of which PGW is a component unit; Dependence on the Public Utility