Rio Tinto (RIO), PT Indonesia Asahan Aluminium, or Inalum, and Freeport McMoran (FCX) have signed a non-binding agreement in relation to the future ownership of the Grasberg mine in Indonesia.

The Heads of Agreement details the proposed principal terms for the sale of Rio Tinto's entire interest in Grasberg to Inalum, Indonesia's state mining company, for $3.5B.

Separately, the agreement sets out a proposed transaction between FCX and Inalum for the latter to buy an additional stake in Grasberg as well as additional terms relating to the future ownership and operation of Grasberg. All parties have committed to work towards agreeing and signing binding agreements before the end of the second half of 2018.