Mullens, who has been chief executive for the past two years, will move into the role of executive director and senior vice president of exploration and development. He will oversee the company's exploration and development of its existing assets and evaluate new business opportunities.
Baker has been chief operating officer of Tethyan since May 2016. Tethyan said during this time he has “successfully acquired and developed significant exploration assets, built a highly capable team and implemented the company's business strategy in the region”.
The company added that Baker has a wealth of experience in the Western Tethyan Mineral Belt and his previous roles include chief geologist at Lydian International's newly discovered Amulsar gold deposit in Armenia and exploration manager for Royal Road Minerals.
Baker founded the private company that secured exploration assets in Serbia, which was then acquired by Tethyan and led to the group’s entry into the Balkan region.
Chairman John Proust said: "The board is very pleased to appoint Fabian Baker as president and CEO, he has been fundamental to the development of the company and we see him as a rising star in the mineral exploration industry. He has an in-depth knowledge of the region's geology, and has developed Tethyan to be a leading player in Serbia and the greater Balkan region.”
He added: "Peter Mullens has guided the company through many important changes during the past two years and the board thanks him for his successful tenure as CEO.”