Higher oil leak estimates resulting from the subsea explosion at BP's Macondo well in the Gulf of Mexico and questions raised during a U.S. Congressional hearing are, among other things, increasing our estimated short- and long-term potential liabilities for BP PLC. BP, a U.K.-headquartered oil major, is reportedly to contribute $20 billion of assets to a specially established claims fund, although these payments do not amount to a cap. We are lowering our long- and short-term corporate credit ratings on BP to 'A/A-1' from 'AA-/A-1+' and keeping them on CreditWatch negative. The ongoing CreditWatch placement reflects our view of the continued uncertainties affecting BP, rapid evolution of the situation, and our reassessment of the longer-term impact of the explosion and