General Motors Co will not make any product commitments solely to achieve a deal with the United Auto Workers union in upcoming contract talks, the automaker's top labor executive said on Monday.

We certainly aren't going to make a decision and make a commitment solely as a way of getting an agreement, said Cathy Clegg, GM vice president of labor relations. If the market doesn't drive it, we can't do that.

Talks between the UAW and the three U.S. automakers begin next week with GM slated to start negotiations on July 27. UAW officials have repeatedly said that adding jobs will be the union's priority in the upcoming negotiations.

This country has to come back with jobs, Joe Ashton, the UAW vice president in charge of GM relations, told reporters, later adding, We've got a tough set of negotiations coming up.

The vast majority of members want jobs and they want job security, he added. They never want to go through what we had to go though in 2009, where they faced bankruptcy and plant closings.

Both Clegg and Ashton said they were optimistic about the talks, but declined to discuss specific negotiation points.

One way for the UAW to boost jobs is by convincing GM to increase vehicle production in the United States, something the union hopes to do at plants with excess capacity.

GM has three such plants in Spring Hill, Tennessee; Shreveport, Louisiana and Janesville, Wisconsin. Clegg said it would be better for GM to first maximize use of current plants.

We need to see some pretty healthy market recovery before we start turning factories back on, she said.

Clegg said GM wanted employees to share in our success. But she also said: Reconstructing what we were is not in the cards.

Clegg and Ashton spoke at an event to mark GM's $328 million investment in its Flint, Michigan, assembly plant to make the next generation of full-size pickup trucks.

The U.S. automaker said as part of the investment it will create or retain 150 jobs at the plant, which opened in 1947 and has about 2,050 employees.

GM is expected to roll out the next version of its Chevrolet Silverado and GMC Sierra pickups in early 2013.

The investment is part of a plan announced by GM in May to invest $2 billion in 17 U.S. plants.

GM has been criticized by analysts for its 122 days of full-size pickup truck inventory in the United States at the end of June. That was 50 percent higher than the 80 days typically preferred and above the industry's still-hefty average of 99 days. GM has said it will reduce its big pickup inventory to a range of 100 to 110 days by year end.

U.S. sales through June of the Silverado and Sierra were up 3 percent and 1 percent, respectively. The Silverado is the No. 2 selling vehicle in the U.S. market behind Ford Motor Co's F-150 pickup.

GM said last month it would close the Flint plant for two weeks in July to conduct maintenance work and prepare for a change to 2012 model-year production.

In January, GM announced plans to add a third shift of 750 workers at the Flint plant in the third quarter to meet increased demand for heavy-duty versions of the big pickups.

GM shares were down almost 3 percent at $28.89 on Monday afternoon, compared with a 1.1 percent fall in the Standard & Poor's 500 Index.

(Additional reporting by Deepa Seetharaman in Detroit; Editing by Matthew Lewis, Steve Orlofsky and Richard Chang)

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