WASHINGTON/NEW YORK (Reuters) - The White House and a top US regulator attacked excessive Wall Street bonuses, as the nation's biggest banks prepare to hand out awards that critics say were made possible only by taxpayer bailouts.

Amid reports of payouts that could average hundreds of thousands of dollars each at some banks, White House spokesman Robert Gibbs said some Wall Street executives "continue not to get it" when it comes to big bonuses at bailed-out companies.

Meanwhile New York Attorney General Andrew Cuomo asked the first eight banks to receive bailout money under the government's much-maligned Troubled Asset Relief Program (TARP) to turn over data on expected bonus payouts in 2009.

These banks are Bank of America Corp., Bank of New York Mellon Corp., Citigroup Inc., Goldman Sachs Group Inc., JPMorgan Chase & Co., Morgan Stanley, State Street Corp and Wells Fargo & Co.

Bonuses typically comprise the bulk of annual compensation for the most highly paid bankers and traders, regularly reaching seven-figure and, occasionally, eight-figure sums.

For some banks, close to 50 percent of revenue can be used for compensation, leaving less available for shareholders who retain power to vote out board directors responsible for overseeing pay in general.

"It's the whole scheme that's problematic," said Charles Elson, director of the John L Weinberg Center for Corporate Governance at the University of Delaware. "These bank compensation schemes are highly problematic, but is the political realm the appropriate place to resolve the issue?"

In letters to the eight banks, Cuomo requested details by February 8 about whether cash or stock is being used in awards, how banks tie pay to performance, how TARP money affected payouts, and whether any awards can be recouped if bank fortunes sour.

"Some banks made a lot of money because, in some cases, taxpayers gave them a lot of money," Cuomo said at a news conference.

Citing the nation's 10 percent unemployment rate, he added: "The taxpayer is still paying that cost."

While large payouts are likely to provoke the ire of Congress, governance critics and shareholders, many banks believe they are needed to keep top talent.

Bank of America is also being sued by the US Securities and Exchange Commission over its role in allowing Merrill Lynch & Co to pay $3.6 billion of bonuses for 2008 despite enormous losses. The bank bought Merrill one year ago.

Spokesman Scott Silvestri said Bank of America will respond to Cuomo's deadline on time, and expects to set 2009 incentive pay by the end of January.

Bank of New York Mellon spokesman Kevin Heine declined to comment. The other original TARP recipients did not immediately return requests for comment.

Gibbs said the president wants in his next budget proposal to include a provision to ensure that taxpayers are repaid in full for financial bailout funds.

According to news reports, the Obama administration is also weighing a fee on banks to recoup more taxpayer funds spent on the financial system rescue.

Meanwhile, a Congressional commission is expected tomorrow to begin a hearing into causes of the financial crisis, including whether the push for outsized pay drove outsized risk-taking.

Speakers expected to testify include Bank of America chief executive Brian Moynihan, Goldman chief executive Lloyd Blankfein, JPMorgan chief executive Jamie Dimon and Morgan Stanley chairman John Mack.