SHANGHAI - Stocks on the Chinese mainland fell on Thursday, dragging down the benchmark index for the second time in three days, on concern Japan's nuclear crisis will cripple the world's third-largest economy.

Jiangxi Copper Co and Zijin Mining Group Co paced losses by metals producers as copper and gold prices dropped. Dongfang Electric Corp plunged among atomic-related companies after the Chinese government suspended approval of nuclear projects. China Yangtze Power Co, a hydroelectric power producer, rallied the most in five months. Yunnan Salt & Chemical Industry Co rose 10 percent as shoppers cleared the shelves of salt, viewed as a defense against radiation exposure.

"Concerns over Japan's radiation risks and their effect on the global economy are overwhelming the market," said Li Jun, a strategist at Central China Securities Co in Shanghai.

The Shanghai Composite Index dropped 1.14 percent to 2897.30 at the 3 pm close, paring its annual gain to 3.2 percent. The CSI 300 Index lost 1.57 percent to 3197.10.

Jiangxi Copper retreated 2.98 percent to 39.04 yuan ($5.94). Yunnan Copper Industry Co lost 1.75 percent to 25.21 yuan.

Copper declined as much as 0.8 percent in London and gold dropped as much as 0.9 percent in Singapore. Silver also fell, and palladium and platinum traded near three-month lows.

"Investors are in panic mode about Japan, and this is weighing on sentiment," Song Lu, an analyst at Soochow Futures Co, said from Shanghai on Thursday. "There are also concerns about liquidity as Japanese investors may pull out of the market in order to channel their funds back to Japan."

Zijin Mining dropped 3.05 percent to 7.63 yuan. The company said its tax rate will rise to 25 percent from 15 percent.

Dongfang Electric sank 7.6 percent to 28.43 yuan, its biggest decline since Nov 12. Nanfang Ventilator Co, the manufacturer of ventilation facilities for nuclear power stations, plunged 10 percent to 48.59 yuan.

China has suspended approval of new nuclear projects and will conduct safety inspections of all nuclear power plants under construction in the wake of the radiation leaks in Japan, the State Council said on late Wednesday.

Related readings:  Radiation fears prompt buying of salt  Debate on nuclear power revived  Anti-radiation-related A shares get a boost  Mainland stocks buck downswing

A gauge tracking utilities on the CSI 300 climbed 1.1 percent, the most among 10 industry groups. China Yangtze Power jumped 3.76 percent to 8.01 yuan.

"Should nuclear power growth slow down, the energy shortfall will be filled by thermal and hydro power," Yang Fan, an analyst at CITIC Securities Co, wrote in a report on Thursday.

Yunnan Salt & Chemical climbed by the 10 percent daily limit to 15.10 yuan.

China's policy tightening has been more effective than expected and investors should "buy into weakness" because liquidity tightening is near its end, according to a Citigroup Inc report.

The brokerage is "bullish" on the outlook for Chinese equities from now through to the third quarter of this year, analysts including Shen Minggao wrote in a report.

China Petroleum & Chemical Corp added 1.06 percent to 8.57 yuan.

The company said it signed a Memorandum of Understanding with Saudi Aramco to take a 37.5 percent stake in the planned 400,000 barrel-a-day Yanbu refinery.

Bloomberg News