Rio Tinto confirmed it was discussing a possible sale of its entire interest in the Grasberg mine in Indonesia to PT Indonesia Asahan Aluminium (Inalum) for $3.5 billion. The company said talks between Rio Tinto, Inalum and Freeport are ongoing, and so far, no agreement has been reached, and there is no certainty that binding agreements will be signed.

Located in the Papua province in Indonesia, Grasberg is one of the world’s largest copper and gold mines in terms of ore reserves and production. It is owned and operated by Freeport Indonesia (PTFI), a subsidiary of U.S.-based Freeport-McMoRan Copper & Gold Inc. Rio Tinto has a joint venture with Freeport-McMoRan for a 40% share of production above specific levels until 2021, and 40% of all production after 2021.

In December, the Indonesian government extended PT-FI’s temporary special license to June 30 to enable normal operations to continue during the negotiation period. In February, PT-FI’s export license was extended to February 15, 2019. Freeport-McMoRan said it continues to engage in negotiations with the Indonesian government to restore long-term stability for Grasberg and it’s looking forward to reaching a mutually positive resolution.

PT-FI is currently mining the final phase of the Grasberg open pit, which contains high copper and gold ore grades. It expects to mine high-grade ore until transitioning to the Grasberg Block Cave underground mine in the first half of 2019.