Oil production from the Organization of Petroleum Exporting Countries fell last month as higher Saudi output failed to offset a West African drop. According to a Dow Jones Newswires survey of industry sources and analysts, crude-oil production from the group averaged 31.669 million barrels a day in September, down about 166,000 barrels a day from 31.835 million barrels a day in August
Oil production from the Organization of Petroleum Exporting Countries fell last month as higher Saudi output failed to offset a West African drop.

According to a Dow Jones Newswires survey of industry sources and analysts, crude-oil production from the group averaged 31.669 million barrels a day in September, down about 166,000 barrels a day from 31.835 million barrels a day in August.

The decline in production was largely driven by lower production in Angola and Nigeria, which a boost in Saudi output was unable to offset.

Production in Angola and Nigeria, which have struggled to sell high-quality crude that carries strong premium compared to others, respectively fell by 97,000 barrels a day and by 92,000 barrels a day. By comparison, Saudi Arabia increased production by 60,000 barrels a day.

Venezuela's output was also down by 60,000 barrels a day, likely because an outage at the country's largest refinery, the Amuay complex, prompted a temporary reduction in production, Vienna-based consultancy JBC said in a note. The declining production "should favour oil prices," Commerzbank said in a note Monday. But the German bank said that "once oil production in Angola and Nigeria returns to normal levels...output should increase again."