ENERGY Resources of Australia (ERA) has increased its expectations for how much uranium oxide it expects to produce in 2012 to between 3,200 and 3,700 tonnes.

The revised forecast issued today came as the uranium producer announced its March quarter operations review, which included a 51 per cent slide in total materials mined.

ERA, which previously expected annual uranium oxide production of 3,000 to 3,700 tonnes, said it had raised its forecast thanks to the earlier than estimated re-commencement of mining in the Ranger Pit 3.

"However, production for 2012 remains highly dependent on the level of actual rainfall encountered for the remainder of the year,'' the company said in a statement.

ERA produced 612 tonnes of uranium oxide in the March quarter, 18 per cent more than in the previous corresponding period, despite lower mill head grade.

ERA said mining operations had still been severely impacted in the latest March quarter because of the water levels deep in the pit.

"As a result, the total material mined and ore mined in the March 2012 quarter was significantly lower than the corresponding period in 2011,'' ERA said.

Total material mined in the March 2012 quarter fell to 1.8 million tonnes from 3.8 million from a year earlier.

ERA said it had brought forward its expected re-commencement of mining in the Ranger Pit 3 to the end of April.

"Dewatering of the pit is scheduled for completion in 2 July 2012,'' it said.

"Until access to the high grade ore at the bottom of the pit is obtained following completion of dewatering, ERA advises that production for the June 2012 quarter is expected to be around the level achieved in the March 2012 quarter.''

ERA said the high level of plant performance achieved in the December 2011 quarter continued in the March quarter, with mill recovery of 88 per cent.

However production in the March quarter was 41 per cent lower than the previous quarter because of lower mill head grade.

ERA said the ore milled in the March quarter was sourced from stockpiled material as it was unable to access the high-grade ore at the bottom of the pit because of the record rainfall in December.

However it expects to step up exploration activity on the Ranger project area, which has been restricted due to heavy rain.

For the March quarter, ERA's total evaluation expenditure rose to $8 million from $3 million a year earlier.

Exploration expenditure totalled $2 million, compared with nil for the March 2011 quarter.

ERA's shares were 1.5c higher at $1.275 at 0950 AWST.