The UAW is hoping to prevent the closure of the 26-year-old NUMMI venture, near San Francisco.

The United Auto Workers has extended its deadline in talks with Toyota Motor Corporation over the fate of the New United Motor Manufacturing Inc. in Fremont, California. The UAW’s existing contract with NUMMI expired at midnight August 9th, but the five-day extension, which could be extended again, was already in place, according to union sources familiar with the bargaining. “We’re still bargaining,” one source said.

The Fremont NUMMI plant employs 5,400 workers.

Jimmy Settles, the UAW vice president responsible for the negotiations, also has skipped the union board meeting in Northern Michigan to attend to the bargaining. Last year, Settles successfully negotiated a package of concessions that helped persuade Mitsubishi to keep open its plant in Normal, Illinois, which was then operating at less than 40% capacity.

Toyota’s new chief executive Akio Toyoda said last week during a visit to the US that the company had not made a decision on closing the Fremont plant, which it operated through a joint venture with General Motors Corporation.

GM, then in bankruptcy, canceled the joint venture in June, leaving Toyota responsible for the venture. In addition, the old contract with the UAW made NUMMI employees the best paid auto workers in the U.S.

Yoshimi Inaba, the new president and chief operating officer of Toyota Motor America and chairman and CEO of Toyota Motor Sales USA, has said that Toyota has too much capacity in the U.S.

Some analysts have suggested the Japanese automaker is prepared to close the plant, which builds compact Corolla sedans and Tacoma pickup trucks.

Harley Shaiken, a labor expert and professor at the University of California-Berkley, said he believed that Toyota senior management would like to avoid a confrontation over the plant, which might be hard to do if the ordered it closed.

“Toyota is very, very sensitive to the political environment in which they operate,” said Shaiken, noting even if the backlash was contained to California, the repercussions for Toyota would still be enormous.

“California is Toyota’s most important market in the U.S. Given the high unemployment rate, the state budget deficit, it would cast a shadow. This is one of the most highly visible auto plants in the world and it has always been one of the most productive,” he said.

“Toyota has strong motivation to settle,” he said.