WASHINGTON (MarketWatch) - General Motors Corp. on Friday paid back taxpayers $1 billion of $50.4 billion in bank bailout dollars it received, according to the Treasury Department on Friday. The repayment is the first quarterly repayment from the embattled automaker, the Treasury said. With the repayment, $119 billion in Troubled Asset Relief Program funds have been repaid, and an additional $45 billion in repayments is expected next week, Treasury said. The Treasury Department estimates that the government could have a loss of $60 billion from its investment in American International Group Inc. and auto companies General Motors and Chrysler.