China's National Energy Administration has told local authorities to curb the irrational development of coal-to-oil and coal-to-gas projects, after new technology sparked an investment spree without regard to environmental and economic realities.

The country will ban coal-to-gas projects with an annual output of less than 2 billion cubic meters, and coal-to-oil projects that produce 1 million metric tons or less, according to an energy administration document published on Tuesday.

Projects larger than those will be subject to regulatory approval from the State Council, China's Cabinet, the administration said.