According to Bloomberg, American International Group (AIG) might sue Morgan Stanley (MS) over mortgage-backed securities that the insurer purchased before the financial crisis.

AIG bought $3.7 billion in mortgage pass-through certificates that were sponsored or underwritten by Morgan Stanley in 2005 through 2007, the New York-based investment bank said yesterday in a regulatory filing. AIG terminated an agreement that had given it more time to bring claims, and the pact will end Nov. 7, according to the filing.