Royal Dutch Shell is in advanced talks with China’s two biggest state-owned oil companies on a possible joint bid to develop the Kirkuk oil field in northern Iraq, the Wall Street Journal reported. Shell, China National Petroleum Corp. (CNPC) and China Petrochemical Corp. (CPC) have yet to determine their respective shares in the venture, a person familiar with the situation said. Shell offered CNPC a 15% stake, but CNPC has sought around 20%. The stake offered CNC was unclear. By including CNPC in Iraq’s first postwar bidding to develop its huge oil and gas fields, Shell hopes to win approval for a contract on the Jinqiu gas field in Sichuan province, the source said. Shell already has a joint venture with PetroChina on the Changbei natural-gas field in northwestern China, and the company has said it wants to increase its involvement in China’s refining sector.