The head of financially troubled insurance giant American International Group (AIG) on Wednesday called on top-earning employees to voluntarily return at least half of the bonuses.

Some employees have already stepped forward to give money back, said Edward Liddy, chairman and chief executive officer of AIG, while testifying under oath at a congressional hearing.

The bonuses could be defended legally as a legal obligation of the company, Liddy told a House subcommittee.

But he said that given the national uproar, he asked those who got "retention payments" over US$100,000 to return at least half of it.

Also on Wednesday, US President Barack Obama said he will ask Congress to pass legislation giving the administration greater regulatory authority over financial institutions like AIG.

He and members of his economic council have started talks with leading lawmakers on such a legislation, said the president at the White House before.

Obama once again assailed AIG's business practices and the millions of dollars in executive bonuses it paid out even as it was 170 billion dollars in debt to government bailouts.

He said he was not trying to quell public anger over AIG. "I think people have a right to be angry. I'm angry," he said.

Charles Rangel, chairman of the Ways and Means Committee of the US House of Representatives, said on Wednesday that the House plans to take up a bill Thursday that would impose a 90 percent tax on bonuses paid to top-earning employees at AIG and other companies receiving big government bailouts.

Under this bill, tax would hit employees who are making more than US$250,000 a year, the head of the tax-writing committee said.

The bill would set a US$5-billion threshold for companies to be covered. It would exclude community banks and other smaller companies that have received bailout money from the government.