China National Petroleum Corporation (CNPC), parent of PetroChina, said on Wednesday it had signed an agreement with Russia's Gazprom to start switching gas supply payments to yuan and rubles.

The agreement was signed between CNPC Chairman Dai Houliang and Gazprom President Alexei Miller during a video conference of the seventh Eastern Economic Forum.

It is regarded as a supplement to the "Sino-Russian Eastern Route Natural Gas Purchase and Sale Agreement."

Miller said the new payment mechanism was "mutually beneficial." But both sides did not reveal when the new mechanism would take effect.

The seventh Eastern Economic Forum opened in Russia's far eastern city of Vladivostok on Monday.