Top 25 Corporations Tax Rate

Many corporations paid little income tax last year to Uncle Sam. In fact, some such as Exxon Mobil paid $14.7 billion in taxes, but none of it to the Federal Government. Because of losses, some, such as GE and Bank of America, get a tax credit. The low tax rates are because of operations overseas. Exxon, for example, creates subsidiaries in Bermuda or the Cayman Islands to hide a lot of their revenue.

http://www.forbes.com/2010/04/01/ge-exxon-walmart-business-washington-corporate-taxes_slide.html