For the first time in its 56-year history, the Business Council -- including top American businessmen -- focused its meeting on just one subject: the soaring U.S. trade deficit.

This intense interest in trade by the chief executive officers of America's largest and most powerful corporations, who make up the Business Council, shows the new importance of trade in the industrial strategy of the major U.S. corporations.

"Never has a single subject dominated the concerns of the business community," said Edmund T. Pratt Jr., chairman of Pfizer Inc. and the man responsible for shifting the focus of this meeting, which ended yesterday, to a single subject.

Because trade is a world problem, Pratt said that the U.S. business leaders invited foreign experts, including the trade ministers of Canada and Mexico, James Kelleher and Hector Hernandez Cervantes; Sir Roy Denman, the European Community's representative in Washington; a Japanese industrialist, Sony Corp. Chairman Akio Morita; and former Japanese foreign minister Saburo Okita.

But the business leaders, long used to making profits by concentrating on America's large domestic market, appeared as confused as Congress and the Reagan administration policy makers on how to turn around the trade deficit.

The captains of U.S. industrial might have been confused about how to solve the trade problems, but they all knew its effects first hand.

They talked of lost markets overseas, increased competition from imports in U.S. markets, lower profit margins and the need to place plants overseas to compensate for the high dollar.

"We are deindustrializing America" because of the strong dollar as companies relocate plants in countries with more favorable exchange rates, Pratt said.

That process of placing plants overseas has profound implications for the U.S. industrial sector as the new production facilities are unlikely to return to the United States when the dollar comes back to equilibrium, he added.

The business leaders blamed the trade deficit almost entirely on the supercharged dollar and, like the administration, they pressed Congress to move ahead on cutting the budget deficit.

"We're being killed by the dollar," said Pratt, whose pharmaceutical company, the world's third-largest, maintains extensive overseas sales and manufacturing operations.

"We've gone too long with a mismatch of fiscal and monetary policy," which has caused a dollar that is overvalued by between 25 and 50 percent, added Edward G. Jefferson, chairman of E. I. du Pont de Nemours & Co.

But not everyone agreed. One high administration official here for the meeting placed the high dollar fourth on a list of causes for the record trade deficit. He listed debt problems of Third World nations, which keeps them from buying American products, first, followed by the failure of European economies to pick up as much steam in the recovery as the United States and the slow pace of Japan to internationalize its yen.

A prime topic of discussion in the Great Hall of the Homestead, where the meeting took place, was France's stubborn refusal to go along at last week's economic summit in Bonn with President Reagan's push for a new round of global trade talks. The Reagan administration sees these negotiations as the key to allowing the most internationally competitive of U.S. industries to increase foreign sales.

These industries include high-technology and service sectors as well as farm sales -- the area that appears to have caused French President Francois Mitterrand the greatest concern. With an election coming up next year, analysts in London and Washington said he appeared concerned that he would lose the votes of French farmers if he agreed to trade talks that could cost them their subsidies.

According to a report delivered to the Canadian Cabinet by Prime Minister Brian Mulroney, Mitterrand also appeared miffed by the power that President Reagan carried to the seven-nation summit as the first among equals.

This personal pique was so great that Mitterrand was reported to have torn up a compromise agreement that Mulroney had worked out with him when he learned the deal already had been approved by Reagan.

The inability of the seven-nation summit to set a date for the start of global trade talks was considered a blow to Reagan.

But Arthur Dunkel, the director general of the General Agreement on Tariffs and Trade, told the business leaders that preparatory talks for the new round will go on this summer -- whether a starting date is agreed to or not.

France, moreover, is not the only holdout. Labor Secretary William E. Brock, who had been the U.S. trade representative, said Third World nations led by Brazil and India are also wary of starting a new round of trade talks. They fear the round will set rules that will keep them out of the new information revolution the way their colonial past prevented them from taking part in the industrial revolution.

Nonetheless, Brock said trade talks will start in 1986. He repeated the threat made before the summit by Secretary of State George P. Shultz that the United States will hold talks with the countries who want new trade rules and leave the rest out.

This could mean a trade round without the participation of Western Europe, because all the countries of the Common Market negotiate on trade under the umbrella of the European Community.

Brock said the talks could focus on the booming nations of the Pacific Rim -- a notion sure to upset the Europeans, who already fear the United States has turned away from its traditional trading partners to concentrate on the new Asia. For the first time, U.S. trade now is greater across the Pacific than accross the Atlantic.

Brock also said nations that participate in the trade talks will receive the "benefits" of new trade rules, while those that do not will suffer "pain" from being left out.

But the Reagan administration push for new trade talks ran into strong opposition here from Sen. John C. Danforth (R-Mo.), one of the leading Senate experts on the subject.

He gave more priority to bringing the dollar into balance with the other currencies of the world and constructing a national policy to "bring fairness" to trade than to holding a new round of trade talks.

"Those are my priorities. That's where the administration should be focusing their attention," Danforth said.

While the idea of a new global trade round received mention in President Reagan's last two State of the Union messages, it gained in importance over the past few months as protectionist pressures mounted and Congress began to demand that the administration retaliate against unfair trade practices, especially by Japan.

The trade round appeared to be the administration's response, an indication that it is doing something on trade.

"I don't understand it," Danforth continued. "I don't understand the enthusiasm for the new round. It's become the centerpiece of administration policy on trade. I think it's something of a diversion."