Tokyo Electric Power Co, the operator of the Fukushima nuclear plant, has posted a massive quarterly loss as it struggles to recover from last year's nuclear crisis.
The group made a loss of 288.4 billion yen ($US3.68 billion) in the first three months of 2012, compared with a loss of 572 billion in the same period last year.
The losses are due to higher fuel costs and compensation payments to those affected by the Fukushima disaster.
TEPCO is now relying on fossil fuels to supply power to Tokyo. It has boosted power generation from its fossil fuel plants, as well as importing oil and gas, to make up for a nuclear power shortfall.
The company said its fuel costs have surged since the disaster, rising nearly 54% from a year earlier.
It has put aside an estimated 161 billion yen for compensation payments related to the disaster from the earthquake and tsunami on 11 March 2011.
However, revenue was up 15.6% in the April-June period from a year earlier to 1.3 trillion yen as the company raised electricity prices to offset its losses. Japan's fiscal year begins in April.
TEPCO has forecast a net loss of 160 billon yen for the year ending next March.
The company was, in effect, nationalised on Tuesday when the government took a 50.11% stake in the group in exchange for a capital injection of 1 trillion yen.