Rio Tinto (RIO.L)(RIO.AX) plans to sell its 27 percent stake in a Chinese aluminium processing joint venture to its partner Shenzhen Zhongjin Lingnan Nonfemet (000060.SZ), China's third-largest zinc producer said on Tuesday.

Rio, which is trying to sell assets to pay off debt, acquired the stake in the joint venture, Nonfemet International (China-Canada-Japan) Aluminum Co Ltd, when it bought Canada-based aluminium group Alcan in 2007.

The transaction was required by Alcan's global industry adjustment, Zhongjin said in a statement in the official China Securities Journal, adding that the value of the deal was $3 million.

Late last year, the Anglo-Australian miner had agreed to sell its half in a Chinese aluminium smelting joint venture to its partner Qingtongxia Aluminium.

Shenzhen Zhongjin Lingnan Nonfemet paid $29.8 million for 50.1 percent in Perilya Mining (PEM.AX) in Australia.

(Reporting by Alfred Cang and Jacqueline Wong)© Thomson Reuters 2009 All rights reserved