BEIJING - A company affiliated with the State Grid announced Friday it would invest 61.5 billion yuan ($9.72 billion) between 2011 and 2015 to build transmission lines and boost electricity supply capacity in northern China's Hebei province.

Jibei Electric Power Company Limited, a subordinated company with the country's largest power supplier, the State Grid, said its investment will facilitate the economic integration of the municipalities of Beijing and Tianjian as well as Hebei province.

Since its establishment about half a year ago, the company now supplies some 70 percent of Beijing's total power demands, while meeting all the electricity demands of the cities of Tangshan, Zhangjiakou, Qinhuangdao, Chengde and Langfang in Hebei.

Yin Jijun, the company's general manager, said he expects power consumption in the five Hebei cities to exceed 200 billion kWh by 2015, with an average annual growth of 8.5 percent.

Apart from the 61.5-billion-yuan investment, Yin said, the company will also invest another 11 billion yuan in upgrading power grids in rural areas of those cities from 2011 to 2015.

Of the 61.5-billion-yuan investment, 23.7 billion yuan will be used to build two ultra-high voltage transmission lines linking the county of Zhangbei in Hebei and the city of Wuhan in central China's Hubei province, as well as Xilingol League of Inner Mongolia autonomous region and the city of Nanjing in East China's Jiangsu province.