Russia 's state-run gas company, OAO Gazprom (GAZP.RS), is in discussions with the China National Petroleum Corp. on advance payments for gas supplies to be delivered via the eastern route, a senior Gazprom official told Interfax Friday.

Gazprom's deputy chief executive, Andrei Kruglov, said an agreement could possibly be reached by the time of the St. Petersburg Economic Forum in June.

Earlier this month, Gazprom CEO Alexei Miller held talks with senior CNPC officials as
Russia and China try to conclude a long-discussed gas-supply deal.

In February, Gazprom said it was aiming to sign a supply contract with CNPC by the end of 2013. Gazprom is seeking to boost supplies to
Asia amid falling demand and regulatory pressure in its most lucrative European market.

Russia has for years sought to reach a deal with China , but talks have been hobbled by disagreements over price and potential routes.