The United Auto Workers, in negotiations apt to set the course of labor relations in U.S. manufacturing for the balance of the decade, yesterday opened contract talks with General Motors Corp. with both sides searching for ways to avoid a strike.

Opening negotiations with the traditional handshake, UAW President Owen Bieber called on the nation's largest automaker to live up to previous job security commitments that have been skirted to allow GM to close four more plants than had been agreed to in the last round of negotiations.

The UAW will repeat the opening-day ritual at Ford today and Chrysler on Friday. The labor contracts with the Big Three automakers, which cover 450,000 hourly workers and almost as many retirees, expire Sept. 14.

The auto talks are the biggest labor negotiations of the year and are expected to set the tone and direction for such issues as job security and labor-management cooperation in other manufacturing industries over the next several years. Dissidents within the union are pressuring the leadership to abandon its cooperation with management.

As important as the negotiations are for both sides, neither the companies nor the union appear to have the strength to withstand a strike, making a walkout of any duration unlikely. The companies are concerned that they no longer can recover any market share they lose during a strike. And the UAW essentially fears that a long strike would tempt the companies to contract out more jobs to nonunion workers.

Although job security has been an issue at the auto bargaining table since the mid-1970s, the problem confronting negotiators at a time of deteriorating auto sales will be to fashion a job security program that distinguishes between permanent and temporary layoffs. The UAW acknowledges the need for the industry to lay off workers temporarily during slow sales periods, but wants to protect against permanent layoffs as the result of structural changes in the companies' manufacturing operations.

The talks with GM are particularly critical for the union. Unlike Ford and Chrysler, which in the past decade have turned more and more to outside contractors to supply parts used in their cars, GM remains a vertically integrated company that manufactures much more of its components than its competitors do. As a result, the UAW has been able to preserve more jobs at GM than it has at Ford and Chrysler.

But union officials acknowledge GM is under increasing pressure from Wall Street to follow the lead of Ford, which by contracting out the work has cut its work force in half since the start of the 1980s.

Noting that GM was the most vertically integrated of the three auto companies, GM chief negotiator Alfred S. Warren Jr., said yesterday that the challenge at this year's bargaining table will be to "find innovative and cost-effective ways to become more competitive in component manufacturing."

After this week's opening ceremonies, the negotiations at all three companies will break into subcommittees for the next several weeks. About three weeks before the contracts expire, the UAW will pick one of the three companies as a strike target if no agreement is reached.

This year, Chrysler is not a factor in the talks. With the company in its current weak financial position, no one is looking for it to set a pattern for anything.

Speculation appears to be divided as to whether Ford or GM will be the target. Companies prefer to be the target because they can have a greater impact on shaping the contract to their specific needs.