Russia may consider allowing Chinese investors more than 50 percent stakes in its strategic oil and gas fields, an official said on Friday, an about-face by Moscow that underlines its need for foreign help to develop energy reserves.

"We have a strategic partnership with China and now decisions are made much faster than before. In particular, we have a gas contract, a second one will be signed soon," he told a conference in the Siberian city of Krasnoyarsk.

President Vladimir Putin has pushed for closer ties with Asia since the European Union and United States imposed sanctions on Russia last year over its role in the Ukraine conflict, plunging relations to lows not seen since the Cold War.

Last year, he oversaw the signing of a deal, valued by Russian state-owned gas firm Gazprom at $400 billion, to supply China with 38 billion cubic meters of gas per year by pipeline from 2019. So far, Russia sells pipeline gas only to Europe.

China's CNPC and Sinopec Group have made upstream investments in Russia but only in quite small projects. CNPC has an exploration block but no production as yet.

Current restrictions allow foreign investors to own up to 50 percent of oilfields with reserves of more than 70 million tons and gas fields with more than 50 billion cubic meters.

Dvorkovich said that 50-50 ownership was "comfortable" for now but added that "if there is a request (for control), we will consider it." He said Russia had not yet decided whether to let Chinese investors take stakes in offshore oil and gas deposits.

Most of Russia's oil production is based in western Siberia, where fields are running out. Any new areas for discovery, such as east Siberia and the Arctic, and hard-to-recover resources, would require foreign assistance.

According to BP, Russia's proven oil reserves, the world's 8th largest, stood at 93 billion barrels at the end of 2013. Its gas reserves were at 31.3 trillion cubic meters, second only to Iran's 33.8 trillion.