Opec is meeting only half its promised cuts in oil supply this month thanks to a big jump in exports from Nigeria and despite a smaller decline in production in Angola, a Reuters survey showed on Thursday.

Supply from the 11 members of Opec with output targets, all except Iraq, has averaged 26.95 million barrels per day (bpd) this month, up from 26.75 million bpd in June, according to the survey of oil firms, Opec officials and analysts.

Supply from the Opec-11 is 2.11 million bpd higher in July than Opec's target of 24.84 million bpd, the survey found, meaning the group achieved just 2.09 million bpd of the promised curbs.

That left compliance at just under 50 per cent, down 5 percentage points from June and the lowest since the current supply targets were adopted in December 2008.

Total Opec supply including Iraq is up 130,000 bpd to 29.23 million bpd, the survey found. – Reuters