General Motors Company and the United Auto Workers union reached a tentative agreement on a new four-year contract late Friday in Detroit, Michigan.

Details of the settlement are being withheld, pending a review meeting with local union leaders and ratification by rank-and-file workers.

The UAW's old agreement expired Wednesday, but the union was barred from striking under the terms of the U.S. taxpayer bailout of GM in 2009.

The union says the new contract covers nearly 49,000 GM workers in the U.S.. The deal protects retirement benefits, improves health care and bolsters a profit-sharing plan.

The UAW chose to complete negotiations with GM first, before reaching deals with Chrysler and finally with Ford Motor Company.