United Steelworkers union members picket outside the Exxon Mobil Beaumont, after being locked out of the plant by the company, in Beaumont, Texas, U.S., May 1, 2021.
United Steelworkers union members picket outside the Exxon Mobil Beaumont, after being locked out of the plant by the company, in Beaumont, Texas, U.S., May 1, 2021. Reuters / ERWIN SEBA

Union workers approved on Saturday a return-to-work agreement that clears the way for Exxon Mobil Corp to end a 10-month lockout at a southeast Texas refinery, a union official said.

The agreement sets the terms for about 600 members of United Steelworkers union (USW) Local 13-243 who Exxon locked out of the Beaumont, Texas, refinery on May 1, 2021, to return to their jobs as early as March 7, said USW international representative Bryan Gross, following the vote.

"It's been a long fight," Gross said. "It's finally coming to an end. It's not where we wanted it to be, but we'll continue fighting for our membership and we'll move forward."

An Exxon spokesperson was not immediately available for comment on Saturday afternoon.

The workers ratified on Feb. 21 a six-year contract, ceding to the company a key demand for control of all job assignments in the 369,024 barrel-per-day refinery and adjoining Mobil 1 lubrication oil plant.

Exxon began the lockout to avoid a threatened strike after three months of negotiations failed to yield a agreement.

Exxon had previously said it would end the lockout after a contract was ratified or the union was removed from the refinery.

The local's future will remain up in the air until the U.S. National Labor Relations Board (NLRB) counts the ballots from a vote concluded in December to remove Local 13-243 from the refinery. The voted was called for by 30% of the union's membership.

The NLRB impounded the ballots until it completes an investigation into the USW's charges that Exxon began the lockout to force the union's removal.