BEIJING, June 8 (Xinhua) -- The new alliance between Rio Tinto and BHP Billiton Ltd. might lead to a monopoly operation and China should be prepared for anti-monopoly measures, warned an expert.

    Mei Xinyu, an economist with the Ministry of Commerce (MOC), told Xinhua Monday that China should closely watch the joint venture process of the two mining giants and be ready to work with other countries to curb market manipulation when necessary, with the help of the anti-monopoly law.

    Rio Tinto scrapped the proposed 19.5 billion U.S. dollars of investment by Aluminum Corp. of China, or Chinalco, on Friday.

    The company announced a cooperative venture with BHP Billiton, which would pay Rio Tinto 5.8 billion U.S. dollars to set up a joint venture to run the iron ore resources of both companies in west Australia.

    It was "something other than economic concern", said Zhang Yansheng, director of the Institute of Foreign Trade of the National Development and Reform Commission.

    Almost half of China's iron ore needed to be imported, more than half of which was imported from Rio Tinto and BHP Billiton, according to Shan of CISA.

    Colin Barnett, premier of Western Australia, told Australian media last Friday China was not on the list of approvals that the two companies needed to obtain.

    Internationally they would need the approval of the European Union and possibly the U.S. Justice Department, apart from investigations at nation and state level, he said.

    Also, Zhang Junsheng, director of the WTO Research Institute at the University of International Business and Economics in Beijing, said China might not have a say on the issue, as neither Rio Tintoor BHP Billiton had an affiliated company in China.