Two out of every three United States corporations paid no federal income taxes from 1998 through 2005, according to a report released Tuesday by the Government Accountability Office, the investigative arm of Congress.

The study, which is likely to add to a growing debate among politicians and policy experts over the contribution of businesses to Treasury coffers, did not identify the corporations or analyze why they had paid no taxes. It also did not say whether they had been operating properly within the tax code or illegally evading it.

The study covers 1.3 million corporations of all sizes, most of them small, with a collective $2.5 trillion in sales. It includes foreign corporations that do business in the United States.

Among foreign corporations, a slightly higher percentage, 68 percent, did not pay taxes during the period covered  compared with 66 percent for United States corporations. Even with these numbers, corporate tax receipts have risen sharply as a percentage of federal revenue in recent years.