"Phase 11 (of South Pars) will be entirely developed by Petropars company," Iran's Oil Minister Bijan Namdar Zanganeh was quoted as saying by the ministry's official website.
Asked whether CNPC International had abandoned the project, Zanganeh said: "Yes, they have".
The other parties to the Iran nuclear deal -- Britain, France, Germany, China and Russia -- have vowed to stay in the accord despite the US withdrawal, but their efforts have so far borne no fruit.
Zanganeh said that Petropars did not take the lead on South Pars from the outset because "we wanted to attract foreign investment for this project" and that Petropars was "supposed to learn alongside these (foreign) companies".