Nidec Shares Slide After Widening Accounting Scandal Hurts Trust

Nidec Corp. shares slid after the company discovered more suspected cases of improper bookkeeping, heightening fears the world’s biggest maker of mini motors may come under regulatory scrutiny for a potential delisting.

The latest revelations emerged from an external probe that began earlier this month when Nidec found evidence of systemic accounting problems. On Friday, it said in a financial report — submitted after a three-month delay — that it had unearthed new problems. Its car inverter business may have for years underreported duties on second-hand goods exported to China, and a Swiss unit may have exported products without completing ...