Simandou, set to be the world's largest and highest grade new iron ore mine, has been the subject of prolonged negotiations due to its complex ownership structure, delays caused by legal wrangling, Guinea's political upheaval and difficulties around construction.

The National Transition Council, which acts as parliament under Guinea's interim regime, voted to approve laws that ratified the agreement, which envisages the completion of construction by end-2024, council spokesperson Mory Dounoh told journalists after the vote.

Rio Tinto owns two of four Simandou mining blocks as part of its Simfer joint venture with China's Chalco Iron Ore Holdings (CIOH) and the government of Guinea. Rio Tinto holds a 53% stake, while CIOH holds the rest.

The two other mining blocks are being developed by Winning Consortium Simandou (WCS), made up of Singapore-based Winning International Group, Weiqiao Aluminium - part of the China Hongqiao Group 1378.HK - and United Mining Suppliers.

(Reporting by Saliou Samb; Writing by Alessandra Prentice, editing by Emelia Sithole-Matarise)