Washington| Rio Tinto is poised to ink within the next fortnight a long-awaited investment agreement for the stalled $US20 billion ($21 billion) Simandou iron ore project in Guinea, which chief ­executive Sam Walsh said would inject “renewed momentum" into the ­development.

Rio has been locked in negotiations with Guinea’s new Conde government, Chinalco and the World Bank’s ­ International Finance Corporation on the controversial project.