Organisation of Petroleum Exporting Countries (OPEC) boosted production in November, according to independent estimates, as Nigeria, Libya and Angola all pumped more oil ahead of the group’s January 1 deadline to cut its collective output, a person familiar with the data said. The OPEC raised production to 33.79 million barrels a day in November from 33.71 million barrels a day in October, the person said, citing data from “secondary sources” such as news agencies and intergovernmental institutions. The person asked not to be identified because the information isn’t public. OPEC members agreed on November 30 to pump less oil for the first-time in eight years, pledging to reduce output by 1.2 million barrels a day to try to end a global surplus and firm up prices. Non-OPEC producers on Saturday reinforced the group’s decision with a commitment to cut an additional 558,000 barrels a day. While Nigeria and Libya were both exempted from cutting, secondary-source estimates of increased output from them and from Angola underscore the challenge OPEC faces in curtailing supply when its accord takes effect. (Wael Mahdi/Bloomberg)