ENERGY Resources of Australia booked a $59.9 million net loss for the first half as it wound down operations at its depleted Ranger pit in the Northern Territory.

The figure was still an improvement on the $121.7m net loss booked for the same period a year earlier, when operations were suspended due to wet weather.

Revenues fell 37 per cent to $147.9m.

Production at Ranger, the world's second-biggest uranium mine by output as recently as 2010, will cease at the end of this year, when ERA will rely on selling stockpiles. The miner said it expected to produce up to 3700 tonnes of uranium this year.

The uranium miner, majority owned by Rio Tinto, said it is still working on a $120m "exploration decline" at the nearby Ranger 3 Deeps deposit to test its suitability for a new underground mine. A final investment decision on the project isn't expected until 2014.

Energy Resources said the uranium market would remain challenging in the short-term. But the company also said the longer-term outlook remained encouraging for established producers as demand continued to grow in China, which was building 26 nuclear reactors.

Energy Resources also said the spot market for uranium was stable.