The ITC's ruling brings an end to what has been an unusual, high-profile feud between two American smokestack industries battered and dramatically altered by global competition: Big Steel and its crucial customer, the auto industry.

The commission's action will lower the price auto companies pay for steel, and bring a similar benefit to other major steel buyers, such as Caterpillar Inc. and Deere & Co.

Those same lower steel prices promise to pressure profits at many American steel producers, however. Shares of U.S. Steel Corp. and other steelmakers declined moderately after the commission's late-morning decision was made public.

The duties the ITC voted to remove "are outdated and hurt American manufacturing competitiveness and U.S. jobs," a Ford Motor Co. trade official said. The import restrictions, he added, have been "needlessly helping a steel industry that is now profitable and healthy."

But the domestic steel industry maintains that the tariffs are needed to prevent the kind of low-priced, sell-at-any-cost import practices that helped bring the industry to its knees during the 1980s and 1990s.

The United Steelworkers union, a prominent backer of the steel industry's efforts to retain the protective tariffs, complained that ITC Commissioners had "turned a blind eye to the unfair trade practices harming our steel industry."

Thursday's decision rewards the automakers' recent lobbying efforts, union president Leo Gerard contended. "Sacrificing one industry to unfair trade in a vain attempt to help another is a losing strategy for American manufacturing," Gerard said.

The dispute involves allegations of `dumping," a strategy in which offshore producers sell their product in this country at below-normal cost. When it decides that such under-pricing is damaging American producers, the ITC can impose tariffs, which raise the price of the offending import.

In 1993, the ITC put such tariffs in place on what is known as corrosion-resistant flat-rolled carbon steel, a high-quality, high-profit margin metal used almost exclusively in making automobiles and appliances.

The ITC had originally set those duties on imports from six nations Canada, Japan, South Korea, German, France and Australia. It separately established tariffs on carbon steel plate, a much less economically crucial product, imported from 10 nations.

Under the law, tariffs are automatically lifted after five years, unless the ITC holds a "sunset" review and finds that the domestic industry would still be damaged if the duties were removed.

When the ITC opened its review of the carbon-steel tariffs in mid-October, automakers with a presence in the U.S. Ford, General Motors, DaimlerChrysler, Honda Motor Co., Nissan Motor Co and Toyota Motor Corp. used the hearings to launch a public attack on the levies.

In general, the carmakers accused the U.S. steel industry of using the import protection to jack up prices and profits. The steelmakers fired back, calling the carmakers' claims "ludicrous" and "laughable."

The standoff underscored a major change in the financial status of the two industries. When the dumping levies were imposed back in 1993, the U.S. steel industry was reeling from a combination of excess capacity and heavy import pressure. Despite the protections, the steel industry entered a painful consolidation in which scores of companies went bankrupt, tens of thousands of steelworkers lost their jobs, and more than 100,000 retirees lost their health benefits.

The reconfigured industry has lower costs, is less burdened with benefit obligations to retired workers, and is dramatically more efficient. The excess capacity that once kept prices low has been brought under control, and the survivors of the steel-industry shakeout are now in much better financial shape.

In contrast, U.S. automakers, particularly Ford and GM, have seen their fortunes decline dramatically over the same period. The domestic producers continue to lose market share to rivals from Asia and Europe. Their costs are bloated by the same retiree pension and healthcare obligations that once shackled the steel companies.

Steel producers argued that the half-ton of corrosion-resistant steel that goes into the average car represents only about $400 in the cost of making the auto. In October, one steel industry official said, "The idea that the profit on $400 of steel is the reason GM is losing billions of dollars is ludicrous."