African Safari Club has ceased trading with thousands of holidays potentially disrupted as a result.
As many as 500 travellers are presently overseas, with an unknown number of forward bookings also affected.
Based in Bromley, Kent, the company offered safari package holidays to Kenya and Egypt.
However, recent unrest in the region has hit bookings.
Passengers who booked flight inclusive packages may be able to claim a refund of the money paid, the Civil Aviation Authority said in a statement.
No further passengers will depart, with those overseas expected to return by next week.
The CAA will be making arrangements to ensure customers of African Safari Club can fly home at the end of their holiday.
All inbound flights from Kenya and Egypt will operate as planned.
African Safari Club also operated a small ocean cruise ship - MS Royal Star - offering cruises to Seychelles, Mauritius, Zanzibar, Madagascar and South Africa.