HONG KONG, May 23 (Xinhua) -- Hong Kong's benchmark index fell 1.31 percent Friday, pulled by the fall of heavyweight China Mobile as investors expect the Chinese mainland to introduce a third mobile operator.

    With the U.S. market stabilizing following two days of slumps, the benchmark Hang Seng Index opened 42 points higher. The index fell 329.05 points, or 1.31 percent, to close at 24,714.07, after trading between 24,693.55 and 25,128.44 during the session. Turnover was 75.26 billion HK dollars (9.66 billion U.S. dollars down from Thursday's 81.11 billion HK dollars (10.41 billion U.S. dollars).

    All the four major sub-index lost ground. The Properties lost most at 1.81 percent, followed by the Commerce and Industry at 1. 57 percent, the Finance at 1.06 percent, and the Utilities at 0.12percent.

    The telecom industry on the Chinese mainland formally started restructuring. China Mobile shed 3.84 percent amid lingering concerns over its monopoly to be at risk despite the merger of China Tietong into its parent China Mobile Group. China Unicom, Netcom and China Telecom surged 11.86 percent, 12.47 percent and 6. 98 percent respectively before trading suspension.

    China Mobile, the world's biggest mobile operator by revenue, ended 3.8 percent lower at 125.10 HK dollars, after falling to as low as 124.10 HK dollars earlier in the day.

    China Unicom, the smaller of China's two mobile phone operators by revenue, rose 11.9 percent to 18.48 HK dollars before it was suspended. China Netcom, China's second-largest fixed-line operator after China Telecom, ended 12.5 percent higher at 27.05 HK dollars before it was halted.

    CNOOC dived 6.58 percent on oil price falling after rise overnight despite upbeat comment by CLSA. PetroChina and Sinopec Corp slid 1.97 percent and 1.23 percent. Cathay Pacific up 0.26 percent, Air China up 1.13 percent, China South Air up 3.64 percent and China East Air up 0.93 percent.