American International Group had an up and down day, as it reported $61.7 billion in losses in the fourth quarter of last year – the worst loss in U.S. corporate history.

Meanwhile, the U.S. Treasury Department agreed to restructure the $150 billion in aid it has provided the company and add another $30 billion in help. The additional aid takes the total provided to AIG to $180 billion.

By comparison, AIG lost $5.3 billion in the fourth quarter of 2007.

Among its losses were $7.2 billion in unrealized losses and credit valuation adjustments at its division responsible for credit-default swaps, AIG Financial Products. Credit-default swaps have been blamed by many for the current economic turmoil in the U.S. and abroad.

The AIG insurance operations lost $2.8 billion in the fourth quarter, with net premiums falling 16.3%, to $9.2 billion. Net premiums earnings decreased 5.9%, to $11 billion.

The new terms ease AIG’s obligations in repaying the federal government and give the government direct control – and cash flow rights – to a number of AIG’s important assets.

“It is becoming less and less credible by the day that AIG’s problems were only at the holding company level,” said Eli Lehrer, a senior fellow at the Competitive Enterprise Institute. “This bailout proves that the idea that AIG only experienced a momentary liquidity crisis is simply wrong. It’s quite possible that we would have done better never to have pumped taxpayer money into the company in the first place.”

Lehrer said AIG’s collapse provides a good reason why the country should explore a plan of national regulatory modernization.

“Massive companies like AIG simply can’t be overseen effectively at the state level,” Lehrer said in a statement. “We need someone, somewhere, who can see a full picture of their finances and, more importantly, provide them with the flexibility to sell the insurance products that customers want and do so on the basis of risk.”