MELBOURNE (Standard&Poor's CreditWire) May 18, 1999--Standard&Poor's today raised the senior unsecured and sovereign foreign currency long-term credit ratings on the Commonwealth of Australia to double-'A'-plus from double-'A'. The Commonwealth's triple-'A' local currency ratings and 'A-1'-plus short-term credit ratings were affirmed. The outlooks on both the foreign and local currency long-term ratings are stable. In a related action, Standard&Poor's raised the long-term foreign currency senior unsecured ratings on the guaranteed debt issues of Export Finance&Insurance Corp. (EFIC) to double-'A'-plus from double-'A'. Standard&Poor's also affirmed EFIC's guaranteed local currency senior unsecured ratings and 'A-1'-plus short-term credit ratings. The upgrade reflects: -- The government's improved external flexibility, emanating from a rapidly declining net