WASHINGTON, Nov. 9 (Xinhua) -- The U.S. Federal Reserve said Monday that GMAC, the former finance arm of General Motors, is the only one of 19 stress-tested banks that needs more aid to meet required financial sufficiency.

    GMAC is expected to meet its remaining buffer need by accessing the Troubled Asset Relief Program (TARP), and is in discussions with the U.S. Treasury on the structure of its investment, the Fed said in an update on the stress tests conducted earlier this year.

    GMAC has been unable to raise the 11.5 billion U.S. dollars it needed after stress test results were announced in May.

    The test results in May found that 10 of the 19 largest U.S. banks needed an extra cushion of capital to withstand deeper losses they would see if the recession worsened. They were required by the central bank to raise a total of 74.6 billion dollars for "capital buffers" in six months.

    The Fed said Monday that they have raised a total of 77 billion dollars excepted GMAC.

    GMAC was the longtime financial arm of General Motors, the largest U.S. automaker until 2006, when GM sold a majority stake. Last December, the ailing GMAC won permission to become a bank holding company, which provided it access to the central bank's lending help.

    GMAC could not raise money in part because investors needed to charge high interest rates to offset the risk that the company could fail.

    The other nine banks including Bank of America Corp., Wells Fargo & Co. and Citigroup Inc., "now have increased their capital sufficiently to meet or exceed their required capital buffers," the Fed statement said.

    Led by the Federal Reserve, supervisors, economists, and analysts who conducted the stress test accessed the amount of capital needed by the 19 largest bank holding companies to withstand greater-than-expected losses and still remain sufficiently capitalized through 2010 to be able to meet the needs of their credit worthy borrowers.

    The release of the assessment results provided important information about the condition of major U.S. financial institutions during a period of high stress and uncertainty, and helped to increase public confidence in the banking system.