MELBOURNE -- Standard&Poor's CreditWire 9/3/97 -- Standard&Poor's today lowered its long-term corporate credit rating on PTT Exploration and Production Public Co. Ltd. (PTTEP) to single-'A'-minus from single-'A'. The rating on PTTEP International Ltd.'s US$200 million unsecured notes due 2006 also was lowered to single-'A'-minus from 'A'. The ratings are removed from CreditWatch where they were placed on Aug. 18, 1997. The rating action on PTTEP reflects the downgrade of the Kingdom of Thailand's long-term foreign currency rating to single-'A'-minus from single-'A' (refer Standard&Poor's press release on the Kingdom of Thailand). The sovereign downgrade reflects the substantial loan losses in the financial sector, as well as the diminution of Thailand's external financial flexibility. Lingering uncertainties