UGMK, one of the largest Russian producers of non-ferrous metals, is working on the acquisition of the assets of gold mining company Petropavlovsk, Kommersant sources said. According to one of them, the company has filed an appropriate application to the Federal Antimonopoly Service. Previously, UGMK had already acquired the rights of claim against Petropavlovsk for a $201 million loan. UGMK, Petropavlovsk and its shareholders did not comment.