NEW YORK (CNN/Money) - Leaders of United Auto Workers union locals gave the green light to concession talks with General Motors Corp., according to a published report, although the union leadership vowed it will only grant relief that does not require a reopening of the current labor contract.

The Detroit News reported Friday that 100 local and regional union leaders whose members work at GM (Research) and its former parts unit Delphi Corp. (Research) voted to support negotiations to reduce the automakers' health-care costs.

"They're saying negotiations are not going to be reopened, but the union side will definitely consider a lot of things," union official Linda Blaine-Motter told the paper. She's chairwoman of the local that represents workers at GM's Warren power-train plant.

The union's four-year pact with GM runs through September 2007.

Tuesday GM Chairman and CEO Rick Wagoner told GM shareholders that the company and union were in negotiations on reducing health-care costs, and said the company needed immediate relief from the rising health-care costs.

He said health care costs the company an average of $1,500 a vehicle more than paid by overseas-based automakers, even at the U.S. plants the competitors operate. He also announced plans to close an unspecified number of plants and trim its unionized U.S. work force by 25,000 by the end of 2008.

The News reports that in March DaimlerChrysler AG's (Research) Chrysler Group exercised a little-known provision in its contract with the UAW to increase out-of-pocket medical expenses for about 35,000 workers and retirees. But even with that contract provision, that cost-cutting move still took months to negotiate, according to the paper.

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