In a draft set of guidelines on deeper reform of the energy business environment, the NEA called for the promotion of integrated natural gas power and renewable energy projects, as well as coordinated development of fossil and renewable energy.

President Xi Jinping this week said China would stop building new coal-fired power stations overseas in Beijing's latest climate pledge, but the fossil fuel still accounts for the bulk of China's domestic energy consumption.

The NEA also advocated improvements in the long-term contract mechanism between energy companies and major energy users in order to ensure stable supply, without specifying what should be done.

The energy regulator said filing procedures for new energy projects should be simplified to promote the low-carbon transition.

"Power supply companies should strengthen power quality management... effectively reduce the time, frequency and impact of power outages," said the NEA.

The draft was released as companies from metal smelters to fertiliser makers have had to reduce production due to power rationing in several Chinese regions.

It is open to public feedback for 30 days.

(Reporting by Min Zhang and Tom Daly; Editing by Hugh Lawson)