WASHINGTON — Bowing to American pressure on the eve of high-level talks to reduce economic tensions, China agreed Thursday to terminate a dozen different subsidies and tax rebates that promote its own exports and discourage imports of steel, wood products, information technology and other goods.

The action mostly affects exports by Chinese companies that have foreign investors or are joint ventures with foreign companies. Nearly 60 percent of Chinese exports are produced by these businesses. Also affected were tax breaks that China gives its own companies if they do not import goods themselves.

There were no clear indications Thursday on which exports, if any, would become more expensive and which imports would benefit, since the precise amount of subsidies that different companies get is not public.

Despite the progress announced Thursday, the Bush administration remained concerned about increasingly aggressive actions by China in recent months to use subsidies, regulations and other government measures to promote national champions in major sectors where foreign countries have been strong, including energy, aerospace, telecommunications and financial services.

The intent of the new agreement, negotiated by Susan C. Schwab, the top United States trade envoy, is to help American companies compete against China. While Ms. Schwab acknowledged that some of the loss of subsidies might be borne by Chinese companies owned in part by Americans, she trumpeted the agreement as a major breakthrough.

“This outcome represents a victory for U.S. manufacturers and their workers,” Ms. Schwab said after the accord was signed by Chinese and American representatives at the World Trade Organization in Geneva. “It shows that President Bush’s policy of serious dialogue and resolute enforcement is delivering real results.”

Ms. Schwab said she hoped that the negotiated settlement on subsidies, after months of litigation at the W.T.O., would improve the atmosphere on other disputes over China’s currency policies, antimonopoly rules, regulations and other practices that seem aimed at discouraging foreign imports and investments.

But no breakthroughs on these other matters appear to be in the offing two weeks ahead of the next round of the “strategic economic dialogue” with China set up last year by Treasury Secretary Henry M. Paulson Jr.

In advance of that session, negotiators led by Ms. Schwab, Paulson and Commerce Secretary Carlos M. Gutierrez are trying to hammer out agreements on food and product safety, improved access to China for American banks and insurance companies and an easing of China’s restrictions on foreign companies.

Lately, however, the administration has charged that China has become more protectionist in crucial areas by erecting nontariff barriers through the use of increasingly sophisticated regulations and government-imposed standards that hurt foreign companies but help domestic ones.

Asked whether the latest agreement represented a trend away from such industrial policy practices, Ms. Schwab was noncommittal. “I would like to think that it’s a signal the trend is changing,” she said. “We don’t know for sure.”

The agreement on subsidies was hailed in the United States by the National Association of Manufacturers and other groups critical of China’s economic practices. But it met with skepticism among familiar critics of China, especially those who charge that China keeps its currency value low to promote exports.

Senator Charles E. Schumer, the New York Democrat, who has criticized China, said the agreement was “a small step on the long road toward playing more fairly” in trade.

Alarmed by a trade deficit that soared to $232 billion last year, and is likely to go much higher this year, Schumer and other lawmakers, including Republicans, are calling for legislation to impose sanctions on China over its failure to let the value of its currency appreciate faster.

The Chinese currency has appreciated 12 percent against the dollar since mid-2005, but it has declined against the euro, making it harder than ever for Europeans to sell to China.

The subsidies affected by the agreement on Thursday were those declared illegal by the United States, Mexico and other trading partners with China, citing W.T.O. laws.

But the move by China will not affect other subsidies on certain kinds of steel products, heavy-duty tires, paper and chemicals that the United States also charges are unfair. The Commerce Department has invited manufacturers of these products to seek relief by requesting duties on these products, and that process continues.

Also unresolved are other American legal actions through the dispute resolution mechanism of the W.T.O.

These actions charge that China discriminates against foreign auto parts by requiring local content for automobiles; fails to enforce copyright and trademark rules on software, videos and other property; and restricts imports of films, music and books.

The Chinese have been irate over American actions that challenge their economic practices at the W.T.O. and over the imposition of duties by the Commerce Department.

But Ms. Schwab said Thursday’s agreement on subsidies vindicated the administration’s approach of using negotiation to resolve disputes and to oppose punitive legislation that is pending in Congress on currency and other policies.