(Reuters) -Teamsters members working at Marathon Petroleum's Detroit refinery have voted to ratify a seven-year collective bargaining agreement, the company and the union said on Sunday, three months after workers walked off the job.

"The process to safely welcome our employees back to the refinery is already in progress," the Findlay, Ohio-based company said.

Over 200 Teamsters at Marathon's Detroit refinery had called for the strike on Sept. 4 after months of pay and safety-related negotiations and mediations with the refiner yielded no results. Their previous contract expired in January this year.

Marathon representatives and Teamsters had several negotiating sessions under a federal mediator since workers went on strike.

The 140,000 barrel-per-day (bpd) Detroit refinery is one of Marathon's 13 refineries with approximately 2.9 million bpd of crude oil refining capacity.

(Reporting by Shivani Tanna in Bengaluru, editing by Deepa Babington and Diane Craft)