In 2016, a Serbian court approved a plan for the restructuring of RTB Bor, writing off 90 percent of its unsecured debt.
The Chinese embassy in Belgrade and representatives of Zijin Mining were not immediately available for comment.
Serbia has tried and failed three times since 2007 to sell the debt-laden mining complex, which suffered a long period of neglect during the Balkan Wars of the 1990s and the country's subsequent international isolation.
It has invested over $1 billion so far in the Balkan country - a candidate for European Union membership - mostly in soft loans, infrastructure and energy projects.
BELGRADE, REUTERS -- China's Zijin Mining Group Co. Ltd. has expressed interest in buying loss-making Serbian copper miner and smelter RTB Bor, which the Balkan state has been trying to sell for the past decade.
President Aleksandar Vucic on Monday met representatives of the Chinese firm, who expressed an intention to invest several hundred million dollars in the business, his office said in a statement.
Last week, Energy Minister Aleksandar Antic said Belgrade would launch a tender for the privatisation of RTB Bor by June, and that a precondition for prospective buyers would be an investment of between $300 and $330 million.
China views Serbia as part of its One Belt, One Road initiative, which is aimed at opening new foreign trade links for Chinese companies.
Vucic's office said Zijin Mining would be welcome to participate in the tender. "The representatives said they have serious development plans both for the RTB Bor company and the region," it said.
The prospective investor would also have to address environmental risks.
To speed up reforms and spur growth, as recommended by the International Monetary Fund, Serbia must dispose of remaining state-run companies.