VIENNA, July 12 (Xinhua) -- OPEC oil output keep rising as Libya and Nigeria pumped more oil in June, the monthly report of the oil cartel showed on Wednesday.

The Organization of the Petroleum Exporting Countries (OPEC) pumped 32,611 million barrels per day in June, 393,500 barrels more than in May. Led by Libya and Nigeria, which are not in the list of oil output cut deal. This is the second consecutive monthly oil production increase of the cartel.

A rebound in Libyan and Nigerian production added pressure to an already amply supplied Atlantic Basin due to a massive increase in U.S. shale oil production, the report said.

According to the OPEC report, the largest producer of the cartel, Saudi Arabia is also pumping more oil in June, the data based on the direct communication from the country shows that Saudi Arabia pumped 10.07 million barrels per day, slightly higher than its quote shared in the joint output cut.