Rio and Chinalco’s Hong Kong listed subsidiary Chalco and consortium partners including Baosteel, the China Africa Development Fund, China Harbour Engineering Co and a branch of China Railway Construction Corp, now hold a respective 53% and 47% interest in the JV which translates into a 50.35% and 44.65% interest in the property with the balance held by the International Finance Corporation, which is part of the World Bank.

The Government of Guinea retains its options for participation in the project and is expected to take up its first share in the near future.

To date, around $3 billion has been spent on the property, including $700 million which was paid to the Guinea government last year as part of a settlement payment.

First shipments from Simandou and the new railway and port are expected by mid-2015, although Rio says it could begin a small trucking operation by early as next year.

When it hits its straps, the operation is expected to produce up to 95 million tonnes of high-grade iron ore per annum.

Shares in Rio Tinto were unchanged in morning trade on $A65.60.