Shares in Energy Resources of Australia slumped almost six per cent as the uranium miner posted a first half loss after suspending operations at its Ranger Mine on above average rainfall.

The company posted a net loss of $121.75 million for the six months to June 30 compared with a profit of $22.68 million a year earlier, Darwin-based ERA said in a statement on Thursday.

Revenue increased 12 per cent to $235.56 million.

ERA said its operating and financial results for the June 2011 half-year were "significantly impacted" by the suspension of processing operations at its Ranger Mine announced on January 28 this year.

"The suspension was taken in response to the significantly above average 2010/11 wet season encountered in the Northern Territory," the company said.

With the restart of the processing operations on June 15, 2011, ERA expects its 2011 production of uranium oxide to be approximately 2,600 tonnes.

The stock slumped 23 cents, or 5.3 per cent, to $4.11 by 1026 AEST.

Additional pond water treatment capacity has been commissioned to help provide earlier and longer access to the bottom of the pit at Ranger.

The company says that, in the short term, the uranium market "appears to be well supplied" due to adequate inventory coverage held by utilities along with increased production, especially from Kazakhstan.

Volatility in the spot price of uranium oxide was likely to continue until the nuclear situation in Japan became clearer and the outcomes of the safety reviews of nuclear power facilities in China were released.

The company says long-term demand is expected to continue to be driven by strong growth in China.

"This is expected to significantly exceed any market contraction as a result of the Japan crisis," the company said.

"ERA continues to envisage a strong future for uranium including continued price and demand growth with long-term demand exceeding planned supply."

The company plans to conduct an expanded exploration program on the Ranger Project area between 2012 and 2014 at an estimated cost of $40 million.

Earnings per share were negative 63.8 cents, compared with positive 11.9 cents a year earlier.

ERA directors decided not to declare an interim dividend for the 2011 financial year, after an interim dividend of eight cents per share the year before.

No final dividend was paid for 2010.