Eastern Airways has taken over three routes previously offered by Isle of Man-based Citywing, which ceased trading on March 10.
Citywing offered scheduled services to various UK destinations to and from the Isle of Man, and between Cardiff and Anglesey (Valley).
From March 13, three routes have been taken over by Eastern Airways: Cardiff-Anglesey (Valley); Isle of Man-Belfast City; and Isle of Man-Newcastle.
The Civil Aviation Authority said in a statement: “Holders of Citywing tickets on the above routes should contact Eastern Airways directly as special fares and, in respect of Cardiff-Anglesey only, the Welsh government has put in place arrangements to allow ticket holders on that route to travel.
“Passengers who have yet to travel on all other Citywing routes will need to make their own alternative arrangements.
“Citywing is not covered by the CAA’s Atol Protection scheme which only covers passengers booked on a package holiday.”
Katy Best, commercial and marketing director at Belfast City Airport, said: “We’re delighted to secure an airline of the pedigree of Eastern Airways on a route that is vitally important to both the Northern Ireland and Isle of Man communities.
“To have filled the void left by Citywing in less than 48 hours is testament to the potential that Eastern Airways recognises in the route.”
Mathew Herzberg, head of commercial for Eastern Airways, said: “By moving fast to protect these vital routes to and from the Isle of Man, this will help to provide continuity for business and leisure travellers.
Ann Reynolds, Isle of Man Airport director of ports, added: “It will be very good news to see Eastern Airways back operating on the island, even more so in continuing the Newcastle and Belfast services in a seamless approach.”
The Eastern Airways daily weekday services from the Isle of Man will be on 29-seat Jetstream 41 aircraft, with fares from £99 one-way, including taxes.
Citywing said the decision to go into liquidation had been taken after an airline which operated flights on its behalf had its permission to fly suspended.