ENERGY Resources of Australia's Ranger mine in the Northern Territory returned to higher levels in the absence of the extreme rain events that dogged the operation in 2011.

But as previously advised by ERA, Ranger was a loss-maker in the June half at the $50 million- $60m forecast range.

The listed Rio Tinto subsidiary said today that production in the June quarter was 632 tonnes of uranium. That was slightly below market expectations for more than 650t but was 661 per cent higher than the rain-affected level in the previous corresponding period.

Production in 2011 was hit by the suspension of processing operations from January 28 to June 15 due to a particularly wet season.

ERA has not updated the market on the size of its expected loss for the June half. It has been doing what it can to reduce costs, revealing that it decided to reduce the quantity of reagents used to extract uranium from low grade stockpiles of ore to "optimise economic returns" in the June quarter.

"This resulted in a decrease in mill recovery compared to the preceding March 2012 quarter," ERA said. While mining operations in the June quarter were again affected by flood water in Pit 3, dewatering operations proceeded ahead of schedule, with full mining access achieved in late May.

"Since that time, the productivity of the mining fleet has been high with the majority of the ore mined for the June quarter having been produced during the month of June 2012," ERA said. The company had forecast output for the full year of 3200t-3700t of uranium, and pointed to increased production in the coming quarters.

Last month, ERA announced a pre-feasibility study costing $57 million for a potential mine-life extending development of the Ranger 3 Deeps deposit.