The New York Times reports: Warren E. Buffett, take note. It is not just a few wealthy individuals paying unusually low taxes to the federal government. Corporate America is not far behind.

A comprehensive study released on Thursday found that 280 of the biggest publicly traded American companies faced federal income tax bills equal to 18.5 percent of their profits during the last three years — little more than half the official corporate rate of 35 percent and lower than their competitors in many industrialized countries.

Mr. Buffett, the billionaire investor, has said that the tax code is unfair, allowing him to pay just 17 percent in federal taxes last year, about half the percentage his secretary paid.

The corporate study, prepared by the left-leaning advocacy group Citizens for Tax Justice, examined the regulatory filings of the companies to compute each year’s current federal taxes. Some of the companies disputed the findings, saying that the study understated their tax payments by omitting deferred taxes that they may pay in future years.

Using information from the companies’ own corporate filings, however, the study concluded that a quarter of the 280 corporations owed less than 10 percent of profits in federal income taxes and 30 companies had no federal tax liability for the entire three-year period.