A Ford spokesman, Mike Moran, said he was aware that Ford would benefit from the tax credit in the bill passed by the Senate. But Mr. Moran said that the credit applied to a range of industries, not just automakers.

A spokesman for General Motors, Greg Martin, said today that the auto companies would only be able to use the tax credits to re-invest in their American operations, not their plants overseas. The credits "will surely have a beneficial impact, which is part of the overall effort to stimulate the economy," Mr. Martin said.

Domestic airlines and manufacturers other than automakers would be eligible to claim the A.M.T. break as well. One lobbyist said that the companies that had sought the tax breaks in meetings with lawmakers included Ford, General Motors, American Airlines, Northwest Airlines and Goodyear Tire and Rubber.

Companies could claim only one of the new tax breaks, which in all, are expected to cost $6 billion through 2018. The jockeying among industry groups, including Realtors, home builders and bankers, is certain to intensify in coming weeks as lawmakers move to reconcile the Senate bill with a more ambitious package of housing legislation now under way in the House.

Lawmakers on the tax-writing House Ways and Means Committee have omitted the corporate tax cuts from their version of the bill in favor of tax breaks for first-time home buyers and developers of low-income rental housing, and more aid for owners facing foreclosure.

Congressional Democrats are also hearing from consumer advocates and other groups who say that the Senate bill does little to help Americans in danger of losing their homes to foreclosure.

“The Senate legislation gave corporations and Wall Street billions in tax breaks,” Terence M. O’Sullivan, the president of the Laborers International Union of North America, said at a news conference on Tuesday to denounce the bill.