The American International Group's former chief executive is moving ahead with a lawsuit against the federal government over its $182 billion rescue of the insurer—even without the backing of the company itself, the New York Times DealBook blog reported yesterday. AIG's former leader, Maurice R. Greenberg, filed an amended complaint against the government yesterday, largely restating his arguments that 2008 bailout of the insurer was unconstitutional and wrongly cheated shareholders out of billions of dollars. His case received support on Monday, when the federal judge overseeing the case granted the lawsuit class-action status.