(Bloomberg) -- OPEC’s oil production edged lower last month as a result of modest declines in Iran, Iraq and Nigeria.

Output from the Organization of Petroleum Exporting Countries declined by 140,000 barrels a day to just over 28 million barrels a day, according to a Bloomberg survey. Nigeria and Iraq saw the largest reductions, cutting about 50,000 barrels each.

Next month output is due to fall more sharply as the group and its allies begin roughly 900,000 barrels a day of new supply cuts announced at the end of an online meeting on Thursday. 

Oil prices faltered after the agreement as traders remained skeptical that OPEC and its allies — which have already reduced output significantly during the past year — are fully prepared to slash supplies further. Consultancy Vanda Insights branded the deal a “confusing, entangled mess” over its lack of detail.

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Group leader Saudi Arabia pledged to keep output near current levels of about 9 million barrels a day during the first quarter, but didn’t promise any extra cuts. 

Thursday’s OPEC+ meeting had been delayed by four days as the group struggled to resolve a dispute over lower 2024 output quotas for African members Angola and Nigeria.

In the final accord, Lagos secured a limit of 1.5 million barrels a day to take effect in January. The Bloomberg survey indicates it pumped 1.44 million barrels a day in November, leaving it some scope to increase production early next year. 

Angola, however, failed to convince the producer group that a target higher than 1.1 million barrels a day was warranted, as its capacity has deteriorated following years of underinvestment. 

Its liaison to the group, Estevao Pedro, rejected the limit and said the country would hold output near 1.18 million barrels a day. Still, the Bloomberg survey estimated Angola’s output at 1.14 million barrels in November, close to the target set by OPEC+. 

Iraq’s production slipped to 4.29 million barrels a day in October as Baghdad struggles to restart an export pipeline halted in March amid a dispute with the Kurdish region and neighboring Turkey.

Iran saw the next-biggest decline, retreating by 40,000 barrels a day to 3.07 million barrels a day, according to the survey. Still, Iranian output remains near a five-year high as the US, eager to tame fuel prices, adopts a softer touch on the country’s oil sales to China.

Bloomberg’s survey is based on ship-tracking data, information from officials and estimates from consultants, including Kpler Ltd., Rapidan Energy Group and Rystad Energy A/S.

--With assistance from Prejula Prem, Anthony Di Paola, John Deane and Fabiola Zerpa.

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