Christopher Dodd, chairman of the Senate banking committee, is poised today to propose his plan for an overhaul of financial regulation. Dodd's proposal would establish a single regulator and would strip banking-oversight authority from the Federal Reserve and the Federal Deposit Insurance Corp., a source said. The plan would also eliminate the Office of Thrift Supervision and the Office of the Comptroller of the Currency, folding them into the new watchdog. "It makes sense to have one regulator that deals with supervision," said Gilbert Schwartz, a partner at Schwartz & Ballen and a former Fed attorney. "You'll see a real battle by the Fed and the FDIC to retain their supervisory authority."