Shares in Energy Resources of Australia fell more than 4 per cent after the uranium miner posted a first half loss because of the suspension of operations at its Ranger Mine in the Northern Territory in January on the back of heavy 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.

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 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 beginning on June 15, 2011, ERA expects its 2011 production of uranium oxide to be approximately 2600 tonnes.

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

The company says 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 becomes clearer and the outcomes of the safety reviews of nuclear power facilities in China are released.

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

"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 was negative 63.8 cents, compared with 11.9 cents a year earlier.

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

No final dividend was paid for 2010.

ERA shares were off 18 cents, or 4.15 per cent, to $4.16 at 8.35am.