BEIJING, June 13 -- The country is to shut down small- and medium-sized coal mines with an annual output under 1.2 million tons over the next three to five years, a Chinese business newspaper said Thursday.

The country has already begun shutting down operations at mines with annual production under 300,000 tons. In coal-rich Shanxi Province, around 20 percent of mines have been closed since reforms began in 2007. The next phase will include mines that produce 450,000 tons per year, which account for nearly two thirds of the national coal output.

"The closure of these coal mines would definitely lead to power shortages in certain areas," the newspaper said.

China's coal consumption exceeded 3 billion tons in 2009, and the country is likely to become the largest coal importer in the world this year, with net imports expected to hit 170 million tons, up from 103 million tons in 2009, according to data from the General Office of the State Administration of Work Safety.

"Improving the country's energy efficiency becomes one of our top priorities," said Li Yizhong, minister of the Ministry of Industry and Information Technology (MIIT) Friday.

In 2009, total investment in energy-efficiency and emissions reduction projects by Sate-owned enterprises totaled 87.84 billion yuan ($12.9 billion).

But the country has backslid on targets set for the 10th Five- Year Plan (2006-10) stating industrial energy consumption per unit of GDP should decline at least 7 percent, according to the MIIT.

"China's energy consumption per unit of GDP in the first quarter increased by 3.2 percent compared to the same period of last year," said Li.