Iran’s target of bringing a swathe of new South Pars phases online by the end of the current Iranian year on 20 March looks to be just out of reach. Development of the world’s largest gas field, shared with Qatar, is a major success for Iran considering the absence of foreign firms, but the pace is slower than planned.

Officials aimed to bring online Phases 13, 14 and 22-24 by 20 March. When running at full capacity these phases will add more than 5bn cfd in gas supply. Iran...