BEIJING, Nov. 6 (Xinhua) -- Chinese share prices recorded mixed performances Tuesday as new market heavyweight PetroChina slumped just over nine percent, causing the benchmark Shanghai Composite Index to close at 5,536.57 points, down 1.74 percent.

    The Shenzhen Component Index on the smaller bourse in Shenzhen ended at 18,120.57 points, up 0.02 percent.

    The combined daily transaction volume on the two exchanges declined by 118.44 billion yuan (15.9 billion U.S. dollars), way down from the previous day's 197.87 billion yuan.

    Only one day after its high-profile trading debut, the PetroChina, which now accounts for 25 percent of the whole weight of counters for the Shanghai Composite Index, plummeted by 9.03 percent.

    With the oil giant as the major driving force, blue chips continued to lead the downward trend.

    Sinopec, China's largest oil refiner, fell 8.78 percent to close at 23.68 yuan. The Industrial and Commercial Bank of China went down 1.57 percent to 8.16 yuan, the Bank of China down 1.25 percent to 7.1 yuan, China Construction Bank down 1.57 percent to 10.63 yuan and China Life, the nation's largest life insurer, down two percent to 66.62 yuan.

    Shang Fulin, head of the China Securities Regulatory Commission, the industry watchdog, said Monday that efforts should be made to strengthen management and supervision over futures and securities trading.

    The October data of the consumer price index, a key inflation indicator, will be released mid-November and is expected to exceed six percent.

    The forecast increased investors' expectations for more interest rate hikes by the central bank, which will be translated into a measure to cool off the sizzling equity markets.

    Some cautious large institutional investors, such as social security and insurance funds, have begun to reduce their holdings of equities, which has added to the continuously slack market mood, observers believe.

    The Hushen 300 Index, tracking one fifth of the total stocks listed on the two bourses, closed at 5,317.55 Tuesday, down 0.8 percent, or 42.76 points, from the previous close.