Billings, Mont.-based Stillwater Mining Company (SWC) got a new CEO yesterday.

On Tuesday, the nation's only producer of platinum group metals announced that after serving as interim Chief Executive Officer since June 2013, Terrell I. Ackerman will be reverting to his role as Vice President of Corporate Development. Replacing him will be new CEO Michael (Mick) McMullen.

McMullen, who already sits on the company's board, is described by the company as having "extensive experience in the metals and mining industry at the CEO and Board level" and "a proven track record of building and leading successful teams, employing strict capital discipline, and delivering outstanding returns to investors."

Over his 21-year career, he has gained experience in iron, gold, copper, and zinc mining in Australia, Europe, Africa, and Latin America. He most recently served as the principal of MRI Advisory AG, a private company focusing on the development of metal and minerals projects in the Americas, Europe and Africa.

Investors yesterday bidding up Stillwater shares by 1.4% in ordinary trading, and a further 2% after-hours Tuesday.