Shanghai's key stock index tumbled to its lowest in nearly 20 months today as producer prices rose and Goldman Sachs Group Inc said the Olympic Games will slow the economy.

The Shanghai Composite Index lost 5.21 percent, or 135.65 points, to 2,470.07 at 3pm.

Losers in the Shanghai market outnumbered gainers 804 to 23.

This was the lowest since December 25, 2006, when the index stood at 2,479.73.

The Shenzhen Composite Index, which tracks the smaller domestic stock exchange, was down 6.55 percent, or 48.97 points, to 698.37.

Shares in industrial sectors, including oil-related stocks, metal producers and coal producers sank after China said today that its factory-gate inflation accelerated a record 10 percent in July, increasing concern that higher costs may fuel higher consumer prices.

Last month's PPI hit the highest level since data became available 12 years ago and will add pressure on the government to adjust fiscal policies to aid troubled companies and curb consumer prices, said analysts.

PetroChina, the country's biggest oil producer and largest market heavyweight, slumped 5.54 percent to 13.80 yuan (US$2.01). Zhongjin Gold Corp, the country's second-largest gold producer, sank 9.88 percent to 36.94 yuan.

China Coal Energy Co, the nation's second-largest coal producer by sales, lost 5.69 percent to 10.77 yuan. Yanzhou Coal Mining Co, the listed unit of China's fourth-biggest coal miner, declined the daily cap of 10 percent to 14.47 yuan.

Power-station coal prices at New South Wales port in Australia fell 2.6 percent to $156.16 a metric ton in the week ended August 8, according to the global COAL NEWC Index. The index reached a record US$194.79 for the week ended July 4.

Datong Coal Industry Co, China's second-largest coal company by capacity, dropped the daily cap of 10 percent to 21.39 yuan.