NEW YORK (Standard&Poor's CreditWire) July 20, 2000-Standard&Poor's today placed Philadelphia, Pa.'s gas works revenue bonds on CreditWatch with negative implications. At the same time, Standard&Poor's affirmed its triple-'B' rating on Philadelphia's gas works revenue bonds, totaling $794 million, as well as its triple-'B'-minus rating on the city's $20 million subordinate bonds. The rating action reflects Philadelphia Gas Works' (PGW) very weak cash flows arising from a convergence of budgeting that did not reflect the trend toward warmer winters; historic ongoing problems with high revenue receivables; and the faulty implementation of a new billing system. Rate relief is needed by this fall. The tariffs that PGW has filed before the state Public Utilities Commission are