China National Petroleum Corp.(CNPC), China's largest oil company, and British oil company BP PLC (BP) have taken over operation and management of Iraq's largest oilfield, Rumaila, in a 20-year agreement, CNPC said in a statement Monday.

CNPC and BP aim to increase output at the Rumaila oilfield 10 percent to 1.17 million barrels per day by the end of the year, the statement posted on the CNPC website said.

Located in southeastern Iraq, the Rumaila oil field has proven reserves of 17.7 billion barrels.