Tokyo Electric Power (Tepco), which operates the crippled Fukushima nuclear power plant, is expected to reshuffle its top management as it reports one of the biggest losses in Japanese corporate history.
The company is to announce full-year earnings at 1530 (0830 GMT) in Tokyo.
Speculation has swirled about the future of the firm, which provides a third of Japan’s power.
It is facing billions of dollars in losses and compensation claims.
On Friday, the Nikkei newspaper and the national broadcaster NHK said that the company would announce a major reshuffle of its top management.
President Masataka Shimizu and Chairman Tsunehisa Katsumata have both stated earlier that they would step down once the crisis was resolved or under control.
A report by Japan’s top-selling Yomiuri newspaper said Mr Shimizu would step down later on Friday.
Tepco declined to comment on the reports when contacted by the BBC.
Mounting costs
The company has been struggling since the earthquake and tsunami hit Japan on 11 March.
Its Fukushima nuclear plant was severely damaged and has been leaking radiation ever since.
Thousands of people have been evacuated from the region around the nuclear plant and the company has been charged with cleaning up the problem and paying compensation to the victims.
According to Bank of America Merrill Lynch, total compensation claims could reach as much as 11tn yen ($134bn; £82.5bn).
Analysts estimate the Japanese utility will reveal a net loss of up to $18bn for the fiscal year which ends on 31 March.
It would be the biggest corporate loss in the country outside the financial sector.
