TriMet and the Amalgamated Transit Union Local 757 have reached a tentative four-year labor agreement, both sides announced Tuesday evening.

The ATU Local 757 represents more than 2,000 TriMet employees, about 80 percent of the agency's workforce.

State Conciliator Janet Gillman helped TriMet and the union negotiate the agreement through 45 sessions. The agreement sets the terms of a new collective bargaining agreement that would be in effect until Nov. 30, 2016. It also resolves two cases pending before the State Court of Appeals as well as cases pending at the State Employment Relations Board.

The agreement must be ratified by the union and the TriMet board.