State Bank of India (NSEI:SBIN) has decided to raise around $2 billion overseas to help Power Finance Corporation acquire entire 52.63% stake in REC. Subject to Reserve Bank of India approval, SBI may either tap SBI London or New York for funds. If this is not available then the bank will seek mandate to raise funds from overseas. In this case, SBI will underwrite the debt backed by government guarantee, Deccan Chronicles reported.