Energy Resources of Australia Ltd. (ERA), a uranium producer controlled by Rio Tinto Group, dropped to the lowest in more than seven years after posting a first-half loss, citing reduced ore processing because of bad weather.

The shares, down 72 percent in the past year, slipped 9.7 percent to A$3.92 at the 4:10 p.m. close in Sydney, the lowest since June 22, 2004. That compares with a 1.3 percent decline in the benchmark S&P/ASX 200 index.

Energy Resources had a loss of A$121.7 million ($130 million) in the six months ended June, compared with a profit of A$22.7 million a year earlier, the Darwin-based company said in a statement today. Earnings were “significantly impacted” by the suspension of processing operations at its Ranger mine in January after heavy rain, Energy Resources said.

Operations at the mine 260 kilometers (162 miles) east of Darwin resumed last month, and full-year production may reach 2,600 metric tons, the company said.

The uranium producer will start construction in May on a A$120 million underground exploration project at Ranger to extend the mine’s lifespan. Mining is scheduled to stop next year, according to the statement.

Energy Resources also said it’s scrapping the development of a plant to process low-grade ore at Ranger, citing high capital costs.

The decision to shelve the plant development led to a charge of A$99 million after tax in the first half following the downgrading of 7,100 tons of ore reserves to resources, according to the statement.

Energy Resources has engaged an external financial adviser to develop a long-term funding plan and is seeking to cut A$150 million in operating costs by 2015, the uranium producer said. As of June 30, the company had A$185 million in cash and no debt.