On 28 October 2016 Rio Tinto announced a non binding agreement to sell its 46.6% stake in the Simandou iron ore project in Guinea to Chinalco. For Rio Tinto divesting Simandou is an opportunity to recoup much of the capital it has sunk into the project. But it means losing control of when the mine is developed and its market power will erode if a fifth major iron ore producer emerges. For Chinalco it will secure one of the world's largest and highest quality iron ore deposits. Simandou also fits with Chinese strategy of building infrastructure in developing countries and increasing captive overseas iron ore sources. Chinalco owning Simandou provides a better chance of the project being developed but could also exert downward pressure on seaborne prices and force higher cost producers to withdraw.