WASHINGTON (Reuters) - Twenty-five of the 100 highest paid U.S. CEOs earned more last year than their companies paid in federal income tax, a pay study by a Washington think tank said on Wednesday.

eBay CEO John Donahoe at the Fortune Brainstorm Tech 2009 in Pasadena, July 23, 2009. REUTERS/Fred Prouser

At a time when lawmakers are facing tough choices in a quest to slash the national debt, the Institute for Policy Studies, a left-leaning group, said it also found many of the companies spent more on lobbying than they did on taxes.

The senior Democrat on the House of Representatives oversight committee, Elijah Cummings, called for hearings on executive compensation “to examine the extent to which the problems in CEO compensation that led to the economic crisis continue to exist today.”

Several companies mentioned in the report took issue with its methodology and said they paid all taxes owed.

General Electric spokesman Andrew Williams called the study “inaccurate” and noted it did not include significant income taxes paid in 2010 for previous years, or state taxes paid. “GE pays what it owes,” he wrote in an e-mail response to questions.

Boeing spokesman Chaz Bickers said the study is “simply wrong”.

Instead of Boeing’s reported “U.S. federal current tax expense” of $13 million which the IPS used, he said a better approximation of the company’s taxes paid would be the $360 million it reported as its net income tax payments, most of which, he says, was federal.

“On federal cash tax payments last year we paid in the hundreds of millions,” Bickers told Reuters. The company also received a $371 million credit from the government last year for overpayment of taxes in the past, and has added 5,000 U.S. jobs this year Bickers says, in part because of Federal tax breaks.

The institute compared CEO pay to current U.S. taxes paid, excluding foreign and state and local taxes that may have been paid, as well as deferred taxes which can often be far larger than current taxes paid.

The group’s rationale was that U.S. taxes paid are the closest approximation in public documents to what companies may have actually written a check for last year. It said deferred taxes may or may not be paid.

The accounting used in SEC filings differs from the accounting used to tally what’s owed on a corporate tax return. Neither the IPS number nor the figure cited by Boeing exactly equals the check written to the IRS, says Scott Dyreng, an assistant professor at Duke’s Fuqua School of Business who studies corporate taxes, and though companies could disclose that figure, don’t have to and don’t do so.

$16.7 MILLION AVERAGE

Compensation for the 25 CEOs with pay surpassing corporate taxes averaged $16.7 million, according to the study, compared to a $10.8 million average for S&P 500 CEOs. Among the companies topping the IPS list:

* eBay whose CEO John Donahoe made $12.4 million, but which reported a $131 million refund on its 2010 current U.S. taxes.

* Boeing, which paid CEO Jim McNerney $13.8 million, sent in $13 million in federal income taxes, and spent $20.8 million on lobbying and campaign spending

* General Electric where CEO Jeff Immelt earned $15.2 million in 2010, while the company got a $3.3 billion federal refund and invested $41.8 million in its own lobbying and political campaigns.

Though the companies come from different industries, their tax breaks fall into two primary areas.

Two-thirds of the firms studied kept their taxes low by utilizing offshore subsidiaries in tax havens such as Bermuda, Singapore and Luxembourg. The remaining companies benefited from accelerated depreciation.

Shareholders have responded favorably when companies in which they invest keep a tax bill low through legal methods, thereby benefiting earnings. But Chuck Collins, an IPS senior scholar and co-author of the report, said that is a mistake.

“I think it’s an exposure of weakness in a company if their profitability is dependent on their accounting department and not on making better widgets,” he said.

In prior reports, Collins said, out-sized CEO pay was often a red flag of bigger problems to come. The IPS has been putting a pay report together for 18 years. Among those whose leaders have made the high pay list in years past, only to have their businesses falter: Tyco, Enron and WorldCom.