Clothes-to-food retailer Marks and Spencer on Wednesday said a cyberattack that affected its online service sent profits sliding in the group's first half.
Net profit plunged 98 per cent to £6.2 million in the six months to late September, compared with profit after tax of £282.1 million one year earlier, M&S said in a statement.
The company halted online sales for about six weeks after hackers targeted the business around Easter, stealing some customer data.
"The first half of this year was an extraordinary moment in time for M&S," its chief executive Stuart Machin said in the earnings release.
"However, the underlying strength of our business and robust financial foundations gave us the resilience to face into the challenge and deal with it."
The group forecast that its second-half profit would be "at least in line with last year, as the residual effects of the incident continue to reduce in the coming months".
M&S flagged in May that the cyberattack would cost the group around £300 million.
On Wednesday, it booked a charge of £101.6 million on dealing with the incident such as fixing systems.
It expects a further hit totalling about £34 million in the group's second half, while M&S has managed to recover £100 million via an insurance payout.
Emphasising its robust underlying performance, sales grew 22 percent in the reporting period to almost £8 billion.
The company's share price dipped 0.1 percent in early London trading.
"Marks & Spencer has laid bare the full impact of a gruelling cyberattack on its earnings," noted Dan Coatsworth, head of markets at AJ Bell.
"Profits have nosedived as shoppers were unable to buy everything they wanted during a catastrophic summer for the retailer."
Cyber gangs have increasingly targeted UK brands and retailers this year, with an incident at Jaguar Land Rover halting production of its cars in early September for one month.
Luxury department store Harrods and the Co-op food chain have been hit by similar attacks.
(AFP)