US Federal Reserve Chairman Ben Bernanke said American International Group Inc. operated like a hedge fund and having to rescue the insurer made him ``more angry'' than any other episode during the financial crisis.

``If there is a single episode in this entire 18 months that has made me more angry, I can't think of one other than AIG,'' Bernanke told lawmakers today. ``AIG exploited a huge gap in the regulatory system, there was no oversight of the financial- products division, this was a hedge fund basically that was attached to a large and stable insurance company.''

Bernanke's comments foreshadow tougher oversight of systemically important financial firms, and come as President Barack Obama seeks legislative proposals within weeks for a regulatory overhaul. The US government has had to deepen its commitment to prevent AIG's collapse three times since September as the company accumulated the worst losses of any US company.

AIG is getting as much as $US30 billion ($47 billion) in new government capital and relaxed terms on its bailout announced yesterday.

The company ``made huge numbers of irresponsible bets, took huge losses, there was no regulatory oversight because there was a gap in the system,'' Bernanke said. At the same time, officials ``had no choice but to try and stabilize the system'' by aiding the firm.