TORONTO (miningweekly.com) – Long-standing Golden Queen Mining president and CEO Lutz Klingmann has resigned with immediate effect.

The project developer on Monday announced that chairperson Thomas Clay would assume the role of interim CEO.

Golden Queen was developing a gold/silver, openpit, heap-leach operation on its fully permitted 50%-owned Soledad Mountain property just outside the town of Mojave, in Kern County, in southern California.

Klingmann, who had served as president of the company since 2001 and CEO since 2009, was instrumental in obtaining project permitting and advancing the project through to project financing and construction, the company said. During his tenure he assembled the team required to complete development and progress the project to the next stage.

Golden Queen also announced that mining veteran Robert Walish had been appointed COO. He had joined the organisation in May as president of the 50%-owned joint venture (JV) entity Golden Queen Mining Company (GQM), of which he had recently been appointed CEO.

Further, Golden Queen director Bryan Coates had been appointed to the GQM board of managers as a nominee of the company, replacing Klingmann. Coates had been a member of Golden Queen’s board since 2013 and was currently the president of Osisko Gold Royalties.

Golden Queen originally used subsidiary GQM to explore and develop the Soledad Mountain project. On September 10, 2014, GQM was converted to a limited liability company (LLC), before entering into a JV transaction with Gauss, through its newly formed, wholly owned subsidiary, GQM Holdings. The JV transaction closed on September 15, 2014.

Upon completion of the JV transaction, both the company, through GQM Holdings, and Gauss each owned half of GQM LLC. In February, Golden Queen incorporated Golden Queen Mining Canada to hold its interest in GQM Holdings.

Gauss is a JV owned 67.5% by Gauss Holdings, an entity controlled by Leucadia National, and 32.5% by Auvergne, an entity controlled by certain members of the Clay family.