CHINALCO and Anglo-Australian miner Rio Tinto yesterday agreed to form a joint venture to explore for mineral deposits in China - the second major tie-up this year after relations soured in 2009.

The venture intends to select between three and five large areas for exploration initially when it will be operational in the first half of 2011, the companies announced yesterday in Beijing.

"This exploration JV is the latest chapter in the rich history of partnerships between Rio Tinto and China," Rio CEO Tom Albanese said yesterday. "The combination of skills provided by Rio Tinto and Chinalco offers great potential to unlock value for mutual benefit."

Chinalco's expertise and deep understanding of the local environment will complement Rio's application of world-leading technologies and experience in operating global mining projects, Rio said.

Chinalco, the biggest shareholder of Rio, will hold 51 percent of the joint venture, and Rio will take the rest. Chinalco will appoint the chairman of the venture's five-member board, with the chief executive nominated by Rio.

Chinalco President Xiong Weiping called the venture a win-win answer to deepen ties and meet market challenges.

In July, Rio agreed to a US$1.35 billion investment from Chalco, Chinalco's listed unit and the nation's biggest aluminum producer, in an iron ore project in Guinea as Albanese seeks more partnerships with China, a key customer which accounts for about a quarter of Rio's total sales.

Rio is mending ties with China after it rejected a proposed US$19.5 billion bid from state-owned Chinalco in June last year. China's arrest of Rio's four Shanghai-based employees for taking bribes and stealing commercial secrets compounded the situation.

Rio and Sinosteel Corp will also extend their Channar joint venture in Western Australia to produce 50 million tons more of iron ore.