The Stillwater Mining Company has opened contract talks with workers at its East Boulder mine in Montana.

The only US-based pgm producer will hold talks with the United Steelworkers union.

An existing agreement between the company and the union's members expires at the start of July.

The initial indications are that the talks have been positive.

"Bargaining teams from the union and Stillwater management established the ground rules and laid the foundation for the upcoming meetings," Stillwater said in a statement.

Last year, Stillwater was hit by strike action at its mine in Nye, Montana. Subsequent negotiations saw 900 workers sign up to new contract arrangements.