BEIJING - China aims to boost its coal production capacity to 4.1 billion tons annually by 2015, the National Energy Administration (NEA) said on Thursday.

The country plans to form 10 coal companies with an annual capacity of 100 million tons each, and another 10 with a capacity of 50 million tons each by 2015, according to a coal industry development plan for the 2011-2015 period released by the NEA.

The 20 companies are expected to account for over 60 percent of the nation's total coal output, the NEA said.

Annual coal output will be controlled at around 3.9 billion tons during the period, according to the plan.

The NEA said it will "rationally control" the scale of coal production, adding that it will slow down construction in central China regions and place more emphasis on west China.

Added projects in the Inner Mongolia, Ningxia and Xinjiang autonomous regions, as well as the provinces of Shaanxi, Shanxi and Gansu, will account for 87 percent of the country's new coal projects, the NEA said.

Meanwhile, China will continue to pursue mergers and acquisitions in the industry to eliminate outdated production facilities.

It plans to cap the number of coal enterprises within 4,000 and to lift the average production scale to more than 1 million tons per year, according to the NEA.