Energy Resources of Australia Ltd. said Thursday it has approved a $57 million pre-feasibility study on the potential for a new underground mine at its Ranger project in Australia's Northern Territory.

The study will run until 2014 and a final investment decision on a new mine is expected to be made late that year, the uranium miner said in a statement.

The current Ranger pit has almost run out of ore. The study will involve drilling an exploration decline through the untapped Ranger 3 Deeps deposit to assess its commercial viability.

Construction of the decline commenced May 1. It involves creating a tunnel through the resource to facilitate closely-spaced exploration drilling