China's benchmark power coal price went down slightly during the past week due in part to high inventory in coal-fired power plants. The Bohai-Rim Steam-Coal Price Index, a gauge of coal prices in northern China's major ports, stood at 570 yuan (around 82.77 U.S. dollars) per tonne on Tuesday, down from 571 yuan a week ago, according to Qinhuangdao Ocean Shipping Coal Trading Market Co. Ltd.

The index was also 1.21 percent lower than that of the same period a year ago.

Despite robust daily consumption, coal stockpiles remained at a high level. On Wednesday, six major coastal power plants saw a total of 16.92 million tonnes of coal inventory, up nearly 6 million tonnes year on year.

Analysts also pointed to growing bearish sentiments on coal prices and a gloomy global market.

The country is in the middle of capacity cutting in its overloaded coal sectors, with plans to reduce a further 150 million tonnes of capacity this year.