"Following a good performance in 2010, non-OPEC supply in 2011 experienced relatively minor growth of 70,000 barrels per day to average 52.4 million bpd," the Organization of Petroleum Exporting Countries said in its report.
It blamed slow development on the lack of new projects, poor weather and political issues.
"Political factors reduced output from the Sudans, Syria and Yemen, for a total loss of 140,000 bpd," the cartel said.
South Sudan in January decided to stop sending crude oil through infrastructure to the Red Sea as retaliation for the alleged theft of oil revenue by the government in Khartoum.
Gulfsands Petroleum, an energy explorer listed on the London stock exchange, announced in December it decided to end exploration activity in Syria because of the fallout from ongoing conflict.
In Yemen, meanwhile, al-Qaida in the Arabian Peninsula, the Yemeni arm of al-Qaida, has targeted the country's oil and natural gas infrastructure amid a tense political climate.
OPEC added, however, it saw better-than-expected performance in North American oil markets, fed largely by shale natural gas and oil sand developments.