Rio Tinto said it has agreed to buy the Aurukun bauxite project in Australia from Glencore and Mitsubishi, bolstering its resources for future production of the key raw material used to make aluminum.

The price of the project, near Rio Tinto's existing bauxite operations in far-north Queensland state, was not disclosed.

The acquisition remains subject to regulatory approvals, Rio Tinto said in emailed remarks.

"If the acquisition proceeds, Rio Tinto would also assess the appropriate regulatory approvals pathway, in consultation with state and Commonwealth agencies, and work closely with traditional owners throughout the next stages of planning and development," the company said.

The project--owned 70% by Glencore and 30% by Mitsubishi--is yet to be granted a mining lease.

Rio Tinto is a top producer of bauxite and has been working on planned expansions to its bauxite operations in Australia as existing mines are depleted.

Glencore confirmed the deal in a separate statement.

It said the joint venture had considered a wide range of options for developing the Aurukun bauxite resource following recent progress on regulatory approvals, and an updated cost estimate and designs.

"After assessing these options, the joint venture believes the introduction of Rio Tinto, as owner of the project, provides the best opportunity for the future development of the resource given their existing bauxite operations in the region," Glencore said.