Workers at a General Motors engine plant in New York set to close in 2008 have rejected a proposed four-year labour contract agreed after a two-day strike last month.

But at least seven other UAW branches have approved the accord, according to the Detroit Free Press.

Union members at the Massena factory voted 172 to 137 against the plan that says the plant will be closed, Local [branch] 465 President Tony Arquiett told the newspaper.

"The members had thought maybe they'd be able to save the plant in negotiations," Arquiett was quoted as saying on Thursday. "It's a big shock to see it in writing like that."

The Detroit Free Press said branches reporting approval of the contract so far represent more than 13,000 of the 73,454 UAW employees at GM. The tentative agreement requires a majority union vote for ratification and UAW president Ron Gettelfinger has asked branches to finish voting by 10 October.

The key to approval, workers have told the Detroit Free Press, is the inclusion in the contract of a detailed list of GM's product plans and prospects for each of its plants. The contract includes details of future work at 55 of its 82 UAW facilities and says GM is closing or considering the future of more than 20 other factories as part of the contract.