Production workers at Volkswagen's only U.S. assembly plant yesterday voted to end a one-week unauthorized strike and return to work while negotiations resume between the firm and the United Auto Workers.

A spokesman for UAW Local 2055, representing about 2,000 employes at the VW plant 35 miles east of Pittsburgh, said the secret-ballot vote was 699 to 390 in favor of returning to work. Two balltos were voided.

Harry Davis, UAW international representative, said the employes would return to work at 6 a.m. tomorrow.

The move to hold the vote, taken at the Import-Export Tire Co. in nearby South Huntingdon Township, had been initiated by the rank and file, who a week ago rejected a company proposal for a three-year contract on grounds it was inferior to current UAW contracts with U.S. automakers.

The striking employes were seeking their first contract with the German automaker, which was heavily wooed by state and local officials to locate here in an effort to boost the economy of this depressed region.

Developments have been watched closely by other foreign auto manufacturers eager to build cars in the United States.

The vote was set after about 500 members of Local 2055, picketing in a pre-dawn rain Friday, closed the sprawling Westmoreland County plant for the fifth day.

The walkout began Monday after a contract offer was rejected. The strike was not sanctioned by the international union, which repeatedly urged the workers to return to the assembly line.

Salaried employes were momentarily blocked from entering the plant Friday.

"It was a volatile situation outside the plant. Management personnel were threatened and couldn't get in," said Richard Cummins, plant manager.

Later, a temporary injunction was issued to limit the number of pickets to three at each gate and to allow free access to management.