China Seeks Oil Security with Stake in Russia Firm

China’s biggest oil company said Wednesday that a $500 million stake it had bought in the newly listed Russian petroleum giant, Rosneft, would help its efforts to secure energy for the Chinese market.

The state-owned China National Petroleum said in a statement published on its Web site that the investment would build on earlier agreements between the two companies to extract, refine and process Russian oil for shipment to China.