SHARES in Shanghai tumbled as the profit falls of heavyweights including Sinopec and China Life fueled investor concerns.

The benchmark Shanghai Composite Index lost 2.33 percent to 3,474.72 after touching an intra-day low of 3,460.26. Decliners outnumbered gainers by 558 to 310, while 89 companies ended flat.

The turnover of A shares shrank to 108.8 billion yuan (US$15.54 billion) from Friday's 183.9 billion yuan. China Life Insurance Co, the country's biggest insurer, said its first quarter profits declined 60.9 percent to 3.47 billion yuan from 8.89 billion yuan due to waning investment returns on the stock market. Its shares fell 4.12 percent to 32.80 yuan.

Liu Jun, a Qilu Securities Co analyst, said he expects China Life's profit to decrease 30.67 percent this year.

China Petroleum & Chemical Corp, better known as Sinopec, posted a 69 percent fall in the first quarter to 6.7 billion yuan. The top oil refiner in Asia only managed to keep in the black after a 7.4 billion yuan government subsidy.

PetroChina and Ping An Insurance (Group) Co are scheduled to post first quarter performance this week.

The expiration of share lock-up periods for Industrial & Commercial Bank of China and China Citic Bank hit the market yesterday, according to Wanlong Securities. Heavy profit-taking also had an impact.

The index is under pressure after it rose 15 percent last week in the biggest weekly gain since 1996, as the index skyrocketed on Thursday on the back of a cut in stamp duty.

"The market is likely to take time to consolidate before a new bullish policy to thrust investment confidence," said Deng Xiyuan, a Minzu Securities Co analyst.

"The stamp duty can only be a short term shot but can't help shift the mid-term trend of the market," Deng added.

ICBC lost 2 percent to 6.36 yuan, while Ping An Insurance shed 3.46 percent to 64.70 yuan.