Tokyo Electric Power Company, the owner of the crippled Fukushima nuclear plant, has requested further financial help from the Japanese government.
TEPCO said clean-up costs and compensation claims for those affected by leaks at the plant may exceed initial estimates.
Radiation leaks at the plant after last year's quake and tsunami saw thousands of people evacuated from the area.
The company has already received 1 trillion yen ($US12.5 billion) in government aid. It was, in effect, nationalised after the government took a 50.11% stake in the group in exchange for the capital injection.
The BBC reports total clean-up costs and claims were initially estimated to be around 5 trillion yen.
TEPCO said it was putting in place further cost cutting measures to save an additional 100 billion yen per year.
It previously set a target of reducing its costs by 336.5 billion yen per year for the next 10 years as part of its restructuring plan.
