State Grid Corp. of China, the country's biggest power distributor, said thermal-coal stockpiles fell 8 percent over two weeks, potentially worsening a nationwide electricity shortage.

Coal stocks at power plants from which State Grid buys electricity dropped to 31.83 million metric tons as of yesterday from 34.64 million tons two weeks ago, Liu Xinfang, a public relations official at State Grid, said by phone from Beijing.

``The coal stocks are still enough for more than 10 days of consumption on average,'' Liu said today.

China's electricity shortage has reached 14,000 megawatts, Liu said. The country tripled coal supplies to the Beijing- Tianjin-Tangshan region to 2.12 million tons in July from last month, ahead of the Olympic Games, he said.