WH Smith shares plunge 42% after retailer’s £30m accounting error

Group cuts profit forecasts and launches review after mistake relating to North American arm

Almost £600m was wiped off the market value of WH Smith on Thursday after the retailer cut financial forecasts and launched an independent review when it discovered an accounting blunder at its North American arm.

Shares plunged 42% after investors took fright at the news that profits at the division had been overstated by £30m.