Rio Tinto and Alcoa have agreed to scrap a bauxite mining joint venture plan in the north Kimberley region of Australia to free-up land for Kimberley National Park.
According to Rio Tinto, the decision to relinquish the area is a vital step in supporting the West Australian Government's plans to establish Australia's largest national park in the region.
Rio Tinto and Alcoa previously signed the 40-year Alumina Refinery (Mitchell Plateau) State Agreement Act, which was intended to facilitate bauxite mining and the development of an alumina refinery in the north Kimberley region.
The company had said that development of a refinery on the Mitchell Plateau would be economically challenging.
Rio Tinto chief executive Sam Walsh said: "The Kimberley National Park can now include the Mitchell Plateau area, where Rio Tinto and other mining companies have undertaken exploration since the early 1970s.
"More than 175,000ha of land on the Mitchell Plateau will become part of what is intended be Australia's largest national park, covering over two million hectares across the Kimberley.
"While the Mitchell Plateau bauxite resource is likely to hold value in the future, the State Agreement Act required the development of an alumina refinery which has always proven to be economically challenging."
Rio Tinto said the company took the decision as part of its long-standing proposal as a member of the West Australian community.
Termination of the act is expected to occur as finalisation of the legislation is being progressed in state parliament.