Rosneft is now one of Russia's top three oil companies

It will lead to Rosneft-branded petrol stations opening across China and could involve CNPC taking a stake in the Russian firm after its share listing.

It was one of a raft of energy deals signed during the visit to Beijing of Russian President Vladimir Putin.

Another will see CNPC help to develop huge gas fields in Siberia.

CNPC already purchases a huge amount of oil from Russia. Last year it imported more than five million tonnes via rail from Rosneft and another Russian oil firm, Lukoil.

China's fast-growing economy has made it increasingly dependent on oil and gas imports and President Putin is eager to exploit the export potential of his country's huge energy reserves.

The two sides have agreed to study the feasibility of building an oil pipeline from Siberia to China.