The licence will be sought by Ivindo Iron SA, a joint venture in which Fortescue holds 80% interest. Africa Transformation and Industrialization Fund owns the rest.

The agreement outlines key terms for the exploration of potentially one of the world's largest undeveloped, high-grade hematite deposits, the Perth-based miner said, adding it expects about $90 million in costs over three years on the exploration program.

"Ivindo Iron plans to immediately commence exploration and studies upon grant of the exploration licences, with the initial focus on exploration works to determine the potential size and grade of the Belinga iron ore deposit," Fortescue said.

The world's fourth largest iron ore miner in December last year signed an agreement with the Gabon government to study the development of the iron ore project.

(Reporting by Navya Mittal in Bengaluru; Editing by Sriraj Kalluvila)