SHANGHAI, Nov 30, 2007 (AP) -- Chinese stocks fell Friday amid renewed fears the government may announce more measures to cool the economy.

The benchmark Shanghai Composite Index lost 2.6 percent, or 131.55, to 4,871.78, after rising 4.2 percent Thursday.

The Shenzhen Composite Index fell 1.7 percent to 1,236.31.

"Many investors are selling at a loss because they're afraid the markets will fall even further, especially if the government announces another round of tightening measures," said Zhou Lin, an analyst with Huatai Securities.

The disappointing performance of PetroChina's shares since they first began trading on the Shanghai Stock Exchange on Nov. 5 was also hurting buying sentiment, analysts said.

PetroChina slid 4.6 percent on Friday to 31.52 yuan. The company, which accounts for more than 20 percent of the Shanghai Composite Index, nearly tripled from its IPO price on its debut. It has since fallen 35 percent as investors took profit on the initial rise.

Most analysts expect the stock eventually to drop to 30 yuan, which would still be twice the price of PetroChina's Hong Kong-listed shares. That's a normal value ratio for shares of other companies listed on both exchanges.

Other blue chips also fell Friday. China Minsheng Bank lost 3.1 percent to 15.10 yuan. China Shenhua Energy fell 4.6 percent to 64.35 yuan.

Friday's decline suggests investors remain gloomy over the outlook for the mainland markets, analysts said.

"There is no sunlight shining through the clouds. Investors are being irrational. If they were rational, they'd buy now because shares have become less expensive after the recent correction," said Zhang Yidong, an analyst with Industrial Securities.