Rosneft sold a 10 percent stake in the Vankor cluster fields in northern Siberia to China’s CNPC Tuesday for about $1 billion.
The Vankor deposit is located in the north of the Krasnoyarsk Territory in central Siberia.
The initial recoverable reserves of oil and condensate in the Vankor field are estimated at 499 million tons of oil and condensate and about 175 billion cubic meters of gas.
As of 2013, there were 266 wells at 31 cluster sites in the Vankor fields yielding a combined total of more than 59,000 tons of oil per day.
Neither company has officially commented on the deal yet.
Tuesday’s sale was made just as a fresh round of EU and U.S. sanctions against Russia and Rosneft were adopted.
The EU said the implementation of the sanctions will be delayed as its determines whether a cease-fire in Ukraine will hold.
The sanctions would further restrict Rosneft’s access to foreign loans, prohibiting the company from receiving any loans with more than 30 days maturity.
Rosneft’s finances have been strained by the EU and U.S. sanctions spurred by Russia’s involvement in the Ukraine.
In August, Rosneft asked the Russian government for $40 billion in aid to alleviate the financial pressure caused by the sanctions.