NEW YORK: Witnesses begin testifying on Tuesday (local time) in the civil trial of American International Group Inc's former top executive, accused of plundering an AIG retirement program of billions of dollars.

Attorney Theodore Wells told jurors on Monday in Manhattan that former Chief Executive Officer Maurice "Hank" Greenberg improperly took $4.3 billion in stock from the company in 2005, after he was ousted by the company amid investigations of accounting irregularities.

"Hank Greenberg was mad. He was angry," Wells said in US District Court of the emotional state of the man who, over a 35-year-career, built AIG from a small company into the world's largest insurance provider.