Harbin Electric Co Ltd will buy four gas turbines from General Electric, including two that incorporate new efficient technology, for use in providing heat to northern China, the two companies said on Friday.

Harbin Electric will purchase the turbines before the end of 2013, according to the terms of a memorandum of understanding signed by the two sides in Beijing. An announcement of the news did not include the amount of the sale or the capacity of the turbines.

GE and Harbin Electric have been partners in China since 2003. In 2010 they formed a joint venture to serve China's wind energy industry.

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"China is installing more wind turbines than any other country in the world and has plans to rapidly expand natural gas power generation," Paul Browning, president and CEO of thermal products for GE Power & Water, said in a statement. The sale will add to GE's "already established relationships to bring wind turbine and gas turbine technology excellence to China," Browning said.

Last week GE introduced a new design of power generation that is an electricity-on-demand approach -- adjusting production quickly in response to fluctuations in wind and solar power. Two of the turbines that Harbin Electric is buying will be of this design, according to the statement.

GE has spent more than $500 million to develop the new technology, which utility operators can use to offset fluctuations in the grid.

In a break with the past, GE designed the first version of this technology to work on European and Asian power grids including China which uses 50 hertz electricity. The United States uses 60 hertz.

GE is the world's largest maker of electric turbines.