The Shanghai Composite declined for 6 out of the last 7 weeks.

Stocks fell, driving down the benchmark index for a sixth week out of seven, on concerns a cash shortage will make it difficult for companies to borrow for expansion and new regulations in Beijing may limit car sales.

SAIC Motor Corp fell to the lowest in four months after China's capital announced measures to restrict the number of new vehicles.

SAIC Motor stock fell to the lowest level in four months after Beijing announced measures to restrict the number of new vehicles. [China Daily]

Baoshan Iron & Steel Co led declines for steelmakers on the prospect that slumping auto demand would curb earnings.

Yunnan Greenland Biological Technology Co paced a retreat for small companies amid speculation higher reserve-requirement ratios for banks have led to a cash crunch.

"It won't be a surprise if the government announces further reserve-ratio or interest-rate hikes by the year's end as curbing inflation is the top priority for decision makers at the moment," said Wu Kan, a fund manager at Dazhong Insurance Co, which oversees $285 million. "The market is also suffering from a liquidity crunch approaching the year's end, and that will keep it fluctuating for the short term."

The Shanghai Composite Index dropped 0.7 percent, to 2835.16 at the 3 pm close on Friday. The index slid 2 percent this week. The CSI 300 Index lost 0.8 percent to 3162.96. The CSI Smallcap 500 Index fell 1.5 percent to the lowest close since Dec 9.

SAIC Motor lost 2.31 percent to 15.63 yuan ($2.36), the lowest close since Aug 26.

Beijing introduced measures including limiting the number of new passenger vehicles in the Chinese capital, to ease congested roads. The government will issue a quota of 240,000 new vehicle license plates through a lottery system next year, with about 88 percent allocated to individual buyers, according to a statement released on Thursday.

Nomura International lowered its forecast for 2011 passenger vehicle sales by 3 percent to 13.4 percent to reflect the potential effects from the policy, Nomura analyst Yankun Hou said in a report on Friday.

"Such measures will have a substantial effect on auto sales," said Hou in the note. "The catalysts will be policy clarifications from central and local governments."

Baoshan Iron & Steel, China's biggest publicly traded steelmaker, declined 0.2 percent to 6.61 yuan. Wuhan Iron & Steel Co lost 0.5 percent to 4.45 yuan.

Aluminum Corp of China Ltd, the nation's largest maker of the metal, fell 2.6 percent on speculation a power supply shortage may curb output and revenue. Yunnan Aluminum Co dropped 1.7 percent to 12.14 yuan.

Aluminum smelters in China may face a "critical shortage" of power that prevents them from ramping up output in the first quarter of 2011, helping to buoy prices as stockpiles decline further, according to Macquarie Group Ltd.

"Our recent visit to Shanxi and Henan provinces suggested the power supply would still be in critical shortage over the winter due to the tight supply of coal," analysts including Bonnie Liu wrote in a report on Friday. Aluminum prices may gain over the next three or four months.

The government has ordered banks to boost their reserve requirements six times this year to curb loan growth and prevent asset bubbles. The seven-day repo rate, which measures lending costs between banks, jumped 150 basis points to 5.67 percent, the highest level since October 2007

The smallcaps gauge fell for a third day, the longest losing streak since September. Even with this week's drop, the index trades at 49.6 times reported earnings, compared with 18.8 times for the CSI 300. Yunnan Greenland plunged by the 10 percent daily limit for a second day to 30.89 yuan, adding to a 22 percent slide this week. Tianjin Zhonghuan Semiconductor Joint-Stock Co slid 8.2 percent to 25.85 on Friday.

China's property stocks may rebound 25 percent from the current level until the middle of January in the absence of further measures to rein in housing prices, according to Guotai Junan Securities.

The rebound may raise developers' valuations to 13 times estimated earnings for 2011 from the current 10.5 times, Sun Jianping and Li Pinke, analysts at the brokerage wrote in a report on Friday.

China Vanke Co, the biggest developer, added 1.9 percent to 9.01 yuan on Friday. Gemdale Corp climbed 5 percent to 6.58 yuan.