Two months after threatening to strike, some 1,500 Teamsters members will vote on a final contract offer from the University of Minnesota, the union announced Tuesday.

The offer calls for a $15-an-hour minimum wage for service workers such as building and grounds crews. It also includes a 2 percent increase for those at the top of the pay scale.

Officials of Teamsters Local 320 said they would submit the proposal, which they termed the university’s final offer, for a vote without a recommendation.

The two sides had been negotiating for nine months, and the union notified the university in November that its members had authorized a strike. The union also represents employees in food service, animal labs and waste management.

Members will have the option to approve a two-year contract or reject it and go on strike, the union said.

The wage offer is consistent with the raises offered to other university employees, according to Patti Dion, the U’s director of employee relations. If ratified by union members, the agreement will go to the Board of Regents for approval.