United Steelworkers union members have ratified a four-year labor agreement with ArcelorMittal USA that will deliver wage and benefit increases to 15,000 workers, including about 300 on Minnesota’s Iron Range.

The deal — which the union and company announced on Thursday — ends months of acrimonious talks over concessions requested by the company. The United Steelworkers (USW) members had voted to allow its leadership to call a strike if it could not come to an agreement with ArcelorMittal, the world’s largest iron and steelmaker.

Leadership reached the agreement in early November. The local units then had to vote on it.

The contract covers union workers at the Minorca Mine and plant in Virginia, Minn., as well as facilities in Pennsylvania, West Virginia, Illinois, Ohio and Indiana.

ArcelorMittal officials in a statement said they were pleased to announce the new contract, which will remain in effect until Sept. 1, 2022.

David McCall, a lead negotiator and director of USW District 1 in Ohio, said the negotiations for the contract were successful because of “the unwavering support of our membership.”

“We successfully defended all of the rights and protections that management sought to reduce, restrict and eliminate,” he said. “On top of that, we were able to make improvements, fill gaps and fix the parts of our contracts that members identified as top priorities.”

USW International President Leo Gerard said the final contract came after “years of hard work and tremendous sacrifice” from workers who previously took wage or benefit cuts to help ArcelorMittal battle a severe industry downturn during 2015 and 2016.

Union officials said the new contract increases wages, bolsters retirement provisions, improves benefits and strengthens contract language for roughly 15,000 hourly production, maintenance, office and technical workers who belong to the union.

The USW also has reached agreements with Cleveland-Cliffs Inc. and U.S. Steel. Cliffs and U.S. Steel both run large iron ore mining and pelletizing operations on Minnesota’s Iron Range.