The union representing 10,000 Stop & Shop workers in Massachusetts voted unanimously to authorize a strike if Local 1445 of the United Food and Commercial Workers can't reach a contract agreement with the company.

The contract expired Saturday at midnight, but store employees will continue working while the bargaining continues. Four other UFCW locals in New England, which are negotiating separate contracts with Stop & Shop, postponed strike authorization votes.

Leaders of Local 1445 have not set a timetable for calling a strike. Stop & Shop, owned by the Dutch company Koninklijke Ahold N.V, wants to cut pensions, increase health care costs, and give new employees fewer benefits, according to the union. The wages being offered are also inadequate, the union said.