Thomas Cook's chief executive, apologized to customers, employees, suppliers and partners.

British travel operator Thomas Cook Group collapsed on Sunday night.

The 178-year-old company said in a statement that its board "concluded that it had no choice but to take steps to enter into compulsory liquidation with immediate effect" after talks on a financial rescue failed. All Thomas Cook bookings have been canceled, the UK Civil Aviation Authority tweeted.

Peter Fankhauser, Thomas Cook's chief executive, apologized to customers, employees, suppliers and partners.

"This marks a deeply sad day for the company which pioneered package holidays and made travel possible for millions of people around the world," Fankhauser said.

"Despite huge efforts over a number of months, and further intense negotiations in recent days, we have not been able to secure a deal to save our business. I know that this outcome will be devastating to many people and cause a lot of anxiety stress and disruption," he added.

Thomas Cook's business of selling flights on its own airline, along with hotel rooms, from brick-and-mortar stores has been under pressure for years from online rivals and low-cost carriers. Brexit has made matters worse by pushing the pound lower (and the company's costs up) and deterring some travelers. The company had reported a loss of £1.5 billion pounds ($1.9 billion) for the six months to March 31.

The collapse of the iconic UK company had ripple effects in Asia. Shares in China's Fosun Tourism dropped by nearly 5% in Hong Kong. The billionaire founder of parent company Fosun International, which owns all-inclusive holiday firm Club Med, is Thomas Cook's largest shareholder, according to Refinitiv data.

"Fosun is disappointed that Thomas Cook Group has not been able to find a viable solution," the company said in a statement. "We extend our deepest sympathy to all those affected by this outcome," it added.

Meanwhile, Thomas Cook India — owned by Canada's Fairfax — said it had nothing to do with the collapse of the venerable British brand and its business was unaffected.

Shares in rival European travel groups got a boost on Monday. Germany's TUI (TUIFF) gained more than 6%, while low-cost airline EasyJet (ESYJY) — which is making a big push into the holidays business — were up nearly 4%.