Zhe ,Netv ijork E:intes July 1, 2013 Big Companies Paid a Fraction of Corporate Tax Rate By NELSON D. SCHWARTZ The biggest, most profitable American companies paid only a fraction of the taxes they would owe under the official corporate rate, according to a study released on Monday by the Government Accountability Office. Using allowed deductions and legal loopholes, large corporations enjoyed a 12.6 percent tax rate far below the 35 percent tax that is the statutory rate imposed by the federal government on corporate profits. The findings come amid rising criticism of the tactics that some big companies use to lower their tax bills. In May, the Senate Permanent Subcommittee on Investigations examined the practices of Apple, in particular how the technology giant had used overseas subsidiaries to sidestep billions in taxes. At a hearing in late May on Capitol Hill, Apple's chief executive, Timothy D. Cook, insisted that the company had fully complied with tax laws and had paid all it legally owed, both here and abroad. Senator Carl Levin, a Michigan Democrat who chairs the subcommittee, and Senator Tom Coburn, an Oklahoma Republican, requested the report to study the issue. The report by the G.A.O., which is the investigative arm of Congress, focused on companies with more than $10 million in assets and what they paid from 2008 to 2010, although it did not address the practices of specific companies. Even so, the findings, along with the earlier reports about Apple, could complicate the efforts to reform the federal tax code's treatment of companies. Chief executives argue that Congress needs to overhaul the corporate tax system because the rates in the United States are well above those of other developed countries. They add that their companies pay taxes around the world, so their federal rate doesn't offer a complete picture of their bill. But legislators like Mr. Levin say the issue is much more complex. The report found that even when