Opec deal would bring subtle shift in market share

If the group delivers on its pledge at the November meeting, some members will lose more than others

If Opec formalises its provisional agreement to limit oil output to a maximum of 33m barrels a day it will force a shift in the group's internal make-up, as well as individual members' percentage of global crude demand. In Q4 2016, global oil demand is expected to rise by 200,000 b/d from Q3 levels, reaching 97m b/d, according to the IEA, before then returning to 96.8m b/d in Q1 next year. Average Opec production was 33.02m b/d in Q3. Barclays estimates group-wide output will increase in Q4 to meet the anticipated rise in global demand, reaching 33.04m b/d, before dropping down to 33.01m b/d at the beginning of next year. If this happens the group's share of the market will remain at around