American International Group (AIG), being kept afloat by a $180 billion government bailout, may sell its downtown Manhattan headquarters.

'AIG is evaluating the potential sale of its headquarters building at 70 Pine Street and the 72 Wall Street building,' said spokesman Mark Herr in a statement. 'This is part of AIG's divestiture strategy and effort to maximize operating efficiency.'

AIG has been the focus of an irate U.S. Congress this week, fuming over $165 million in bonus payments to executives after the massive bailout. Both buildings were constructed in 1932 and have been owned and operated by AIG since the 1970s. The insurer's roots date back to China in 1919.

The 66-story 70 Pine Street building is topped with a Gothic-like spire, and was the tallest building in downtown Manhattan prior to the building of the World Trade Center.

Herr said 'market interest' would help AIG decide the best way to proceed with the sale. He declined to say what price tag AIG was seeking for the properties. CB Richard Ellis (CBG.N) is representing AIG.

It has also put the prized building in the Otemachi section of Tokyo that overlooks the Imperial Palace up for sale and is in talks to sell other real estate assets around the world.

Merrill Lynch (BAC.N) is running the auction for the Tokyo building. AIG has been trying to dispose of assets and businesses since last year in an effort to pay back debt to the U.S. government.

AIG, once the world's biggest insurer by market value, averted bankruptcy in September with an $85 billion federal bailout. The rescue later swelled to as much as $180 billion.

AIG shares closed 42 cents higher at $1.38 on the New York Stock Exchange.