LONDON — A second British vacation company has gone out of business, the aviation regulator said todday, the same week the country's third-largest tour operator collapsed.

On Friday, the big XL Leisure Group PLC went into liquidation, leaving about 50,000 of its customers stranded abroad.

The smaller K & S Travel ceased trading on Saturday, Civil Aviation Authority press officer James Hotson said. But its customers' return trips are covered by a bond, he said. The group specialized in travel to Turkey.

"It's a very small operation, there are 150 passenger currently overseas. They can continue their holidays as normal," Hotson said.

About 400 people with reservations would have their vacations canceled and receive full refunds, he said.

K & S's telephone line was dead on Sunday, and the company's Web site was down.

Airlines and travel groups have been badly hurt by soaring fuel prices and a weakening economy. Many have trimmed their schedules; others have gone out of business.

Two weeks ago, the Canada-based budget carrier Zoom, which offered service to Britain, shut down. Silverjet, a business-class carrier based at Luton north of London, ceased operations in June.