In 2006, Bear Stearns was the number one underwriter of mortgage-backed securities, with 11% of the US mortgage securities market.

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Beyond the approval by the accountants and lawyers, the US stock market watchdog, the Securities and Exchanges Commission, has also "approved our last version" of provisions which was published in the 2000 annual report last February, Mr Schmidt said.

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But while many major international banks have seen large writedowns in the wake of rising defaults among the sub-prime mortgage market, the majority of China's US mortgage-backed securities were underwritten by US government agencies such as Fannie Mae.

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Adding to the difficulties, the US Securities and Exchange Commission has been looking into Groupon's accounting and disclosures to the stock market.

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