Under the agreement, the Papua New Guinea government paid Nautilus $7 million, which entitles it to a 15% stake in the project, with an option to increase it by another 15% in the next 12 months.
Despite objections from several groups, the Harper government declared over the weekend the humpback a "species of special concern" under the Species at Risk Act (SARA).
The mine has an initial annual production capacity of 35 million tonnes and is a key part of BHP's plans to lift capacity from its Pilbara operations to 220 million tonnes a year.
