OPEC+ has pushed back a scheduled review of its members' long-term oil production capacity, according to sources cited by The Straits Times, after the war involving Iran disrupted expansion plans inside the group.

The delay affects the producer group's regular exercise of assessing and revising the capacity baselines used to allocate output quotas among its members. That review determines how much crude each participating country is entitled to pump under the group's supply-management agreements, so any deferral leaves existing quota arithmetic in place for longer than planned.

The proximate cause, according to the sources, is the conflict involving Iran — an OPEC member exempt from the group's quota system. The war disrupted expansion plans tied to Iranian capacity, complicating the data picture on which a credible recalibration of baselines would depend. Israel and Iran traded strikes over a 12-day period in June before a ceasefire took hold, and the disruption to Iranian production and export flows during that window has left the group working with an incomplete picture of actual versus nameplate capacity in the region.

The capacity review matters commercially. OPEC+ baselines feed directly into quota allocations for the eight members currently executing coordinated production increases, and they frame the group's planning horizon for how much spare capacity the market can call on. A delay does not change current output targets; it defers the point at which those targets would be rebalanced against revised capacity estimates.

Neither OPEC nor officials in Vienna have confirmed a new timetable for the review, and the sources did not specify the length of the postponement. The group's published production schedule for the quota-bound members runs through late 2026, with the next full ministerial meeting set for November 30, where the agenda will signal whether the capacity question returns before year-end.

The watch item: the OPEC+ ministerial on November 30, and any interim announcement on when the capacity review resumes.