General Motors and the United Auto Workers announced Wednesday they have reached tentative agreement on a new contract aimed at ending a monthlong strike.

Details of the deal weren’t released, but the UAW said it had “achieved major wins.” GM’s brief statement merely confirmed that an agreement had been reached.

The four-year contract is “likely to include some pay raises, lump sum payments to workers, and requirements that GM build new vehicles in U.S. factories,” reports the Associated Press. GM had previously announced plans to close four U.S. factories.

The deal will not immediately end the strike. The 49,000 union members will stay on the picket lines for at least two more days, and possibly longer, while two UAW committees and rank-and-file members consider the new contract and vote on whether to accept it. 

“The walkout, the first against a Detroit automaker’s nationwide operations since 2007, has left a mounting economic toll since it began on Sept. 16,” reports the New York Times. “It has cost the union, its members and G.M. itself hundreds of millions of dollars in lost dues, wages and revenue, as well as idling truckers and suppliers that serve the automaker.”

If the GM deal is approved, it will serve as a model for the UAW’s negotiations with Fiat Chrysler and Ford.