Brighton-based Holidays 4 UK has gone into administration, stranding as many as 12,000 holidaymakers overseas.
Ian Oakley-Smith and David Chubb of PricewaterhouseCoopers (PwC) have been appointed as joint administrators of the company, which also traded as Aegean Flights.
The tour operator was based near Brighton and sold package holidays and flights to Turkey.
It has 18 employees, most of which are now expected to lose their jobs.
The company holds Air Travel Organiser’s Licence (ATOL) No 4097, is a member of ABTA and had an annual turnover of approximately £35 million.
Around 12,000 travellers are currently overseas and have been immediately impacted.
Oakley-Smith said: “The company has suffered because of the difficulties faced by the travel industry during 2010 and 2011, as a result of the economic downturn.
“The director has determined that the business is no longer able to trade and placed the company into administration.
“The company will cease operating with immediate effect.
Passengers booked with the company on all future flights, including tonight’s flight from Manchester to Dalaman at 21:00, should not travel to the airport and should refer to the CAA for more information.
The Civil Aviation Authority (CAA) will be responsible for the repatriation of those who have booked flights as part of a package holiday, as this is covered by the ATOL scheme.
The ATOL scheme may also reimburse passengers who booked a package holiday and have not yet travelled.
Passengers who booked through a travel agent are advised to contact that agent in the first instance as they may be able to assist with information regarding repatriations and/or in making a claim to ATOL.
More information for those overseas can be found on the CAA website.