HAGERSTOWN, MD. -- A United Auto Workers official says a decision by Mack Trucks Inc. to recall 313 workers is an apparent bid to blunt a strike that it fears will occur when its contract with the union expires Oct. 20.

The truck maker, faced with a possible strike, recalled the workers last week, said James Stewart Jr., president of UAW Local 171. The union has said that it believes Mack is using the extra workers to stockpile parts to continue production in the event of a strike.

James A. Santanasto, a spokesman for the Allentown, Pa.-based truck company, said the recall reflects a need for workers caused by attrition.

"We have had a large number of people we have lost through attrition, mostly from retirement, and that group had to be replenished," Santanasto said.

The recall is a reprieve for nearly half the 700 production employes taken off the lines at the Hagerstown plant since July. The plant now has 2,750 union workers -- the most since early last year, when the truck manufacturer began hiring other companies to produce some parts made at the Hagerstown operation.

Santanasto said that as of last week, 150 of the 313 recalled workers had returned to work.

Stewart said jobs for the recalled workers might not last long if a federal judge upholds a 5 1/2-year pact negotiated between Mack and the union this spring. The pact, covering workers at Hagerstown and three other plants, has not been signed because of disputes over wording in the agreement.

Company and union negotiators reached the tentative job-saving contract with a handshake in April and agreed to hash out the language later. They met several times, but could never come to terms over contract language.

In July, Mack filed suit against the UAW to end the stalemate. Stewart said a court hearing on Mack's suit to enforce the pact, which was filed in U.S. District Court for the Eastern District of Pennsylvania, was expected to begin later this month.

If the judge rules that the proposed agreement is not valid, as the union contends, Stewart said there still could be time to negotiate a new pact before the current contract expires Oct. 20.

"If he {the judge} would say there is a 5 1/2-year agreement, the future of those 700 people doesn't look very bright," he said. "Why would you need a strike bank {stockpile of parts} if you've got a 5 1/2-year agreement?'