Sibanye-Stillwater (SBSW) said Wednesday its workforce ratified a new collective bargaining agreement with the United Steelworkers International Union covering the Stillwater East mine and Columbus metallurgical facility in Montana.

The ratification ends a strike that started Sept. 3, with employees expected to return to work Friday, the company said.

The agreement is effective retroactively from June 1 this year through May 31, 2029. It includes a 4.5% wage increase in the first year, followed by increases equal to the greater of 3.5% or the Consumer Price Index in the second year and the greater of 3% or the CPI in the third year, Sibanye-Stillwater said.

The company said the agreement supports the transition to fully mechanized mining, team-based incentives and changes to certain legacy benefits at its US platinum group metals operations.

Shares of the company were down 4.2% in pre-bell activity on Wednesday.