The Organization of Petroleum Exporting Countries added just 90,000 barrels a day in December. OPEC made only part of its planned production increase last month, with supplies hampered by disruptions in two of the group’s African members. The Organization of Petroleum Exporting Countries added just 90,000 barrels a day in December, as a boost by Saudi Arabia was offset by losses in Libya and Nigeria, according to a Bloomberg survey. The OPEC+ coalition led by Saudi Arabia and Russia has been restoring production halted during the pandemic, and on Tuesday agreed to press on with further increases at a rate of 400,000 barrels a day. But the process has been hindered as some members struggle with investment constraints and internal instability. The coalition’s travails are helping to support oil prices even as global markets tip back into oversupply, with Brent crude futures trading near $80 a barrel in London […]