Move underscores push by Chinalco away from aluminium

* Copper finds at home could reduce China's need for imports

SYDNEY, Nov 25 (Reuters) - Rio Tinto said on Friday it would initially explore for copper in China under a newly-formed partnership with state-owned Chinalco before branching out into other commodities.

"The JV's initial priority will be exploring for copper, with plans to expand into coal and potash in the future," Rio said in a statement.

The partnership, called Chinalco Rio Tinto Exploration Co. Ltd, has been officially registered as a business in China, according to a statement on Rio's website.

China is the world's biggest importer of copper and is looking to reduce its dependence on overseas supplies.

Rio Tinto and Chinalco signed an agreement in June 2011 to form the joint venture.

Chinalco holds a 51 percent interest and Rio Tinto 49 percent.

Chinalco has sought to diversify its business away from aluminium, and its listed unit Chalco has already agreed to invest $1.35 billion in the Simandou iron ore deposit in Guinea, another joint project with Rio Tinto.

For its part, Rio Tinto has been anxious to rebuild ties with Chinalco after rejecting a $19.5 billion investment bid from the Chinese firm in 2009. Rio Tinto has also been trying to repair the damage caused by the jailing of four of its Shanghai staff last year for stealing commercial secrets and taking bribes.