Political leaders have been warning for years that failure to take the next step in liberalizing the rules of international commerce would plunge the world into a gloves-off trade war.

Now, with only weeks to go before the deadline for the latest massive restructuring of world trade, the talks have run into major roadblocks here and overseas.

In Europe, farmers in Germany, France and elsewhere appear willing to scuttle an agreement rather than do without the subsidies that a new accord would wipe out.

In the United States, companies as large and diverse as B.F. Goodrich Co., Motorola Inc. and Corning Inc. appear to have decided that they, too, would oppose a deal that would leave the United States with no weapons with which to fight other countries that "dump" goods cheaply and unfairly in their home market.

The Bush administration has staked much political capital on overcoming these forces. "We will have hand-to-hand combat in trade" if the talks fail, Agriculture Secretary Clayton Yeutter said yesterday in Sao Paulo, Brazil, Reuters reported. "The accords we seek in Geneva are absolutely essential to our future prosperity," said U.S. Trade Representative Carla Hills. Economists in Japan and Western Europe echo these themes.

A steep decline in tariffs and the breaking down of other barriers to trade over the past 40 years has made it cheaper and easier to sell products ranging from fingernail-sized semiconductors to giant jet passenger planes around the world. This has been widely credited with producing a 50-fold increase in world trade, which many believe has led to the growth of the world economy faster than in any other four decades in history.

Yet the General Agreement on Tariffs and Trade (GATT), as the trade accord is called, covers only about one-third of commerce between nations. The current "round" of talks -- dubbed the Uruguay Round after the country in which they began four years ago -- are designed to widen the GATT net and modernize it to include areas of finance and the world of computers that didn't exist in the post-World War II world in which GATT was created.

With negotiations in their final five weeks, Bush administration trade officials believe they can satisfy complaints of major U.S. companies and bring them on board. Harry Freeman, executive director of the MTN Coalition, a business group that favors the round, believes that there is hidden support for the talks that is being overwhelmed by more active companies raising their concerns.

As it tries to deal with troubles at home, the administration is growing increasingly worried about the disarray within the European Community, which has steadfastly refused to talk about making the sharp cuts in agricultural subsidies that many other nations are demanding.

"The Europeans are in a very serious impasse," said Julius Katz, deputy U.S. trade representative. "I don't know at what point we become absolutely desperate ... {but} the opportunity to work something out narrows with each passing day."

The European position is complicated by German elections Dec. 2 -- the day before the wrap-up meeting for the trade round is set to begin in Brussels. Chancellor Helmut Kohl, concerned that compromising on farm trade would cost him the votes of German farmers, told EC President Jacques Delors last week to water down a proposal for 30 percent cuts in agricultural supports -- government payments that shore up the incomes of less efficient European farmers.

EC sources in Brussels predicted that a compromise will be forged today at a meeting in Luxembourg of farm and foreign ministers who will make a last-ditch effort to resolve the subsidy impasse. The sources said the EC would provide special payments to Germany to help inefficient farmers there survive the loss of production subsidies.

And even if the Europeans reach a common negotiating position among themselves, it could fall short of what is acceptable to the United States and other countries.

All this gives scant comfort to U.S. negotiators, who in the closing weeks of the talks find themselves fighting a two-front war -- with eroding support on the home front diverting them from tough negotiations in Geneva.

Chinks developed in business support for the trade talks this summer, after major corporations took a closer look at direction the Uruguay Round was heading.

"They looked at the possible trade-offs and became much more cautious with their support," William T. Archey, international vice president of the U.S. Chamber of Commerce, said.

Previously, the round had been under attack from farm and business interests that stood to lose from the talks.

Even export-oriented U.S. manufacturing companies are far from united in their view of the trade talks, complicating the positions of U.S. negotiators.

In Geneva, for instance, competing U.S. industrial interests are clashing in full view of incredulous negotiators from other nations, who are more accustomed to those differences being thrashed out behind closed boardroom doors. The main argument concerns how far GATT rules should go in curbing the United States's use of its own unfair trade law -- a bone of contention among a host of countries that say disputes should be settled in GATT, not unilaterally.

The list of companies involved includes some of the biggest and most competitive of the Fortune 500 giants. In the most public of the battles, they are arguing over the fine points of arcane trade laws banning "dumping," the cut-rate sale of imports at below what it costs to make them. Each group has its Washington lawyers lobbying foreign delegations in Geneva and using Congress to keep the heat on U.S. negotiators.

On one side are companies such as Caterpillar Inc., Hewlett-Packard Co., International Business Machines Corp., 3M Corp., NCR Corp. and Philip Morris Inc. -- working under the umbrella of the Emergency Committee for American Trade -- that favor making it harder to win dumping cases. Attorney Gary Horlick, in Geneva this week, said his clients are concerned that they could be targets of dumping cases on their exports.

But a group of equally competitive companies -- including Corning, W.R. Grace & Co., Motorola Inc., B.F. Goodrich Co. and major American steel and semiconductor makers -- want to make sure that the GATT talks strengthen rules against dumping. "We are very concerned about the erosion of the trade remedy laws," said Alan W. Wolff, the attorney for that group.

Similarly, semiconductor manufacturers and other high technology companies want the United States to retain the right to punish companies that try to ship in products using pirated technology.

American Telephone & Telegraph Co. and its competitors for long-distance business -- MCI Communications Corp. and U.S. Sprint Communications Corp. -- have focused on attempts to bring service industries under international trading rules.

Robert E. Allen, AT&T chairman, wrote Hills that a draft agreement on telecommunications trade would freeze other countries' monopolies while keeping the U.S. market open, thereby hampering American companies' attempts to expand overseas while subjecting them to continued competition at home.

"We'd like to see a services agreement," but the telecommunications issue could be a deal breaker for AT&T, said Frederick Tipson, deputy director for government affairs at AT&T International.

Staff correspondents William Drozdiak in Paris and Paul Blustein in Tokyo contributed to this report.