ENERGY Resources of Australia said it has defined a significant extension to the open-pit at the Ranger mine in the Northern Territory.

ERA , which produces about 10 per cent of the world’s uranium, said it had defined an exploration mineralisation target potentially containing 30,000 to 40,000 tonnes of uranium oxide.

Exploration at Ranger has been focused on defining potential for an extension to the open-cut pit, or possible establishment of underground operation.

ERA, which is majority owned by Rio Tinto , has been exploring the Ranger 3 Deeps area adjacent to the open-pit for the past two years.