HONG KONG - Huaneng Power International Inc said the country's regulator has approved its plan to build two coal-fired generating units with an investment of 5.09 billion yuan ($800.4 million).

In a statement to the Hong Kong stock exchange late on Thursday, Huaneng said the National Development and Reform Commission had given approval for its plan to build two 600 megawatt generating units for its 80 percent-owned Shanxi Huaneng Zuoquan Power Plant in northern China.

Emission indexes at the plant would meet government requirements on environmental protection, the company said.

Hong Kong-listed shares of Huaneng were down 2 percent at 0240 GMT on Friday against 1.63 percent rise in the Hang Seng Index.