Insurance giant American International Group (AIG) reportedly intends to sue Bank of America (BAC) for billions of dollars over hundreds of poor-quality mortgage-backed securities sold at the height of the housing collapse, adding to a mounting list of suits against the Wall Street giant. 

The move, which adds to a slew of investors trying to reclaim billions in losses caused when BofAs mortgage unit Countrywide knowingly sold bad loans, sent shares of Bank of America tumbling more than 10% to a two-year low of $7.31 Monday morning.

AIG, which is still largely owned by taxpayers as a result of its 2008 government bailout, was down more than 7% to a 52-week low of $23.15.

The AIG suit will seek to recover more than $10 billion in losses on $28 billion of investments, according to a report by the New York Times, representing one of the largest mortgage-security-related lawsuits filed by a single investor.

A group of 22 investors including the Federal Reserve Bank of New York and BlackRock Financial Management, was awarded $8.5 billion by BofA earlier this year over the same troubled loans.

That payment had hardly touched the investors request that the Wall Street bank repurchase $47 billion in sour mortgages that Countrywide sold some three years ago in the form of bonds, but it still marked the largest ever settlement by a financial-services company.

Like those investors, AIG claims BofA and its Merrill Lynch and Countrywide units misconstrued the quality of the mortgages and knowingly sold bad loans to investors, according to the Times, citing three people familiar with the matter.