The joint-venture company proposed by General Motors Corp. and Toyota Motor Corp. will seek a radically different relationship with the United Auto Workers, one based on "mutual trust" and Japanese production methods, former Labor secretary William J. Usery said yesterday.

"We're talking about building a whole new workplace," said Usery, who would serve as labor adviser to the new car company, which would operate at a former GM plant in Fremont, Calif.

Final approval of the joint venture rests with the Federal Trade Commission, which is reviewing the proposal for possible antitrust violations. Usery said he expects that decision this summer.

"We've got to change old attitudes. Presumably, if we have a union and we get a contract, we're going to get a relationship based on mutual trust instead of hatred," said Usery, who is a former leader of the machinists union and onetime director of the Federal Mediation and Conciliation Service from 1973 to 1976. He was secretary of Labor in the Ford administration.

The UAW formerly represented employes at the Fremont plant, which GM closed last year because of declining sales of Chevrolet Celebrity and Oldsmobile Ciera passenger cars that had been produced there.

At its peak in 1980, the plant had 6,000 workers. The joint venture will employ 3,000 workers in the production of 200,000 small, front-wheel drive cars annually.

Union representation in the new company remains an open question until the joint venture is approved and new managers and employes are in place, Usery said. But he said the joint-venture management "would not stand in the way to keep UAW representation from coming about."

Also, Usery said GM and Toyota have "agreed that the laid-off workers from the former General Motors Fremont facility will be the primary source for recruiting workers." However, he emphasized that those workers would serve as a primary employment source for the new plant primarily because of geography.

Seniority in the now-defunct GM Fremont operation would have no bearing on employment in the joint-venture plant, Usery said. Nor will joint-venture managers discriminate against applicants who have had no previous experience in the plant, he said.

"There is no successor agreement" with GM and the UAW in the new operation, said Usery. "We are not bound by previous GM rules," he said.

The main objective of the joint-venture managers would be to eliminate old work rules and other labor-management practices and attitudes that contribute to production inefficiency, Usery said. For example, production in traditionally operated domestic auto plants often has proceeded under rules setting up inflexible job classifications. Skilled craftsmen, for example, did work classified as skilled even though a lesser skilled person might have been able to perform the same task.

Traditional plants also have tended to be top-heavy with managers, with "checkers checking checkers checking checkers," according to a longstanding criticism of the old system.

The result has been a Japanese cost advantage over U.S. automakers of $1,500 to $2,000 per car, according to an often-quoted differential, although that figure lately has come under attack by some industry analysts who say it is exaggerated.

In any case, Usery said at a breakfast meeting yesterday that the joint venture can ill afford old production and labor-management techniques if it is to be successful.

Both labor and management know that "the old methods will not work any longer," he said. "We want to, in the event that we have a union, see if we can develop a non-adversarial relationship."

To help achieve that goal, joint-venture managers, who will be chosen by Toyota, will send many of their American workers and managers to Japan to learn Japanese production techniques, Usery said.

Those techniques involve the use of more flexible work rules and reliance on better cooperation between labor and management. Workers are given a greater say in production matters, and the layers between workers and management are fewer.

Ronald Dore, a professor at London's Technical Change Center who has studied Japanese factory systems, puts it this way: "The Japanese-type cooperative approach rejects the zero-sum view of worker-capitalist relations--the idea that everything that benefits the one side must represent an equal and balancing loss to the other."

UAW, GM and Toyota officials yesterday declined comment on that concept. But the union, whose leaders have had informal contacts with Usery in his new role, said they were happy to have him serve as labor adviser to the joint venture.

"As we've said all along, we look forward to establishing a relationship with the manager of the joint venture," said UAW Vice President Owen Bieber, who is expected to replace Douglas Fraser as the union's president next week.