CHICAGO (AP) -- Workers at a Chicago Ford plant have overwhelmingly rejected a tentative four-year contract agreement, union officials said Thursday.

Seventy-seven percent of the more than 2,300 workers at the Torrence Avenue plant voted against the deal, according to Grant Morton, United Auto Workers Union Local 551 plant chairman.

While the union has generally called the contract a good deal, the membership "obviously had multiple issues. We'll talk to the membership and find out what those issues are," Morton said.

UAW's 41,000 Ford workers will continue voting into next week, but so far more workers have voted no than yes. In Michigan earlier this week, 51 percent of more than 2,500 workers in one local union voted against the deal. Workers at a plant in south suburban Chicago Heights will vote starting Thursday.

The contract calls for a $6,000 signing bonus and profit-sharing instead of annual raises. It also created 1,100 jobs in Chicago, but those new workers would be paid less than existing staffers to save money.

The international union's executive board will take a strike authorization vote if workers reject the contract nationally, and plans are already under way in case that happens, Morton said.

"We were given direction earlier today to prepare for a strike," he said.