Nidec shares fell as much as 18 per cent after a report that the Japanese auto parts maker will book a ¥1tn ($6.3bn) impairment charge and dismiss its chief executive. The world’s largest motor manufacturer plans to recognise the charge retroactively for the financial year to March 2026, according to business magazine Diamond. ¥600bn of the losses relate to asset value assessments for businesses under reform, including home appliances, while ¥300bn stem from corrections of improper accounting. Nidec had previously warned that ¥250bn of asset impairments might still be booked.

The company’s board voted to remove chief executive Mitsuya Kishida, with a potential announcement as soon as this week. The fresh writedowns are a blow to Nidec’s efforts to move past an accounting fraud and about 1,000 cases of alleged manufacturing misconduct. The parts supplier to Volkswagen and BMW faces the risk of delisting in October if it cannot prove internal controls and governance have been overhauled. Nidec did not immediately respond to a request for comment.

The Kyoto-based company, which supplies technology for drones, robots, and electric vehicles, cut ties with its founder Shigenobu Nagamori earlier this year. An internal probe into a 2024 payment by a Chinese subsidiary to a supplier spiralled into a wider investigation. In March, an independent commission found widespread accounting fraud. Nidec’s share price is now a third of its 2021 peak. The company has proposed 11 new board members and increased independent directors to 10 out of 13.