Canada’s largest private-sector union says it has reached a tentative agreement with General Motors on a new deal for some 4,600 auto workers.

Unifor announced the agreement Saturday morning and said it would cover workers at auto plants in Oshawa, Ingersoll, St. Catharines and Woodstock.

“Our bargaining committee worked diligently to reach these agreements, which deliver strong income and benefit gains, amid some of the most challenging times in our history,” national president Lana Payne said in a statement.

Negotiations began on Aug. 10, according to the union, after deals between Unifor and Ford Motor Company were agreed upon and wrapped up.

The tentative agreement with General Motors still needs to be ratified by union members, but Unifor’s bargaining committee said it was unanimously endorsing the agreement.