BEIJING, June 14 -- China's coal production declined sharply in May as measures to cut capacity began to take effect, official data showed Tuesday.

Total output of coal mining companies with annual revenue of more than 20 million yuan (3.04 million U.S. dollars) dropped 15.5 percent year on year in May, according to the National Development and Reform Commission.

Output accumulatively decreased by 8.4 percent in the first five months compared with the same period last year, the commission said, without providing further details.

Since April, major coal-producing provinces and regions reported sharp output declines as the industry moves to address overcapacity. Coal output in Shanxi Province, the country's largest coal-producing region, was down 21.3 percent year on year in April.

However, the price of coal picked up slightly in May as power plants consumed more coal to meet increasing electricity demand from households tuning up the air conditioning as a respite from the summer heat, according to the commission.