A $5 billion-worth cooperation deal was signed on Thursday between Russia's En+ Group and China's Export-Import Bank of China (China Eximbank or EIBC).

The deal was inked on the sidelines of the ongoing 2011 St. Petersburg International Economic Forum which went underway on Thursday.

The En+ Group is a leading diversified mining, metals and energy group in Russia while the China Eximbank is one of the largest international lenders.

Chinese President Hu Jintao and his Russian counterpart Dmitry Medvedev witnessed the signing of the cooperation deal. The two presidents will attend the official opening of the annual forum on Friday.

The China Eximbank will finance the construction of thermal and hydro power plants, the development of coal fields and iron ore mining as well as copper concentration projects in Eastern Siberia undertaken by such En+ Group companies as the EuroSibenergo, Tuva Mining and SMR.

Total installed generation capacity with the China Eximbank finance in Eastern Siberia will be 3 gigawatts.

"The agreement will significantly strengthen cooperation between Russia and China and be a milestone in the large-scale development of Eastern Siberia," said En+ Group CEO Artem Volynets.

"China Eximbank is delighted to have partnered with En+ Group in these important projects and to have provided the financing necessary to assist in the development in Eastern Siberia," said Li Ruogu, chairman and president of the Chinese commercial bank.

"The agreement that has been forged between our businesses is a further example of the strong ties that exist between our countries and provide further optimism for the potential for Sino-Russian cooperation in the areas of trade and economic development."