Tokyo Electric Power Company, the owner of the Fukushima nuclear plant damaged in earthquake and tsunami in March, has reported a quarterly loss of 571.8 billion yen ($US7.4 billion).
The loss includes 400 billion yen put aside to compensate victims of the disaster, which forced 80,000 people to be evacuated from the area around the Fukushima plant.
TEPCO gave no forecast for the full year. The company said there was too much uncertainty over the ongoing crisis.
TEPCO may have to pay compensation of up to $US130 billion over the incident.
Last week, Japan's parliament approved a plan - including financial contributions from taxpayers and other utilities - to help the company compensate victims of the disaster at the plant.
TEPCO has said it aims to start accepting claims in September and making payments in October.