ADMINISTRATORS for Flybe have been unable to find a buyer for the collapsed airline.
Interpath said it will begin "winding down the business" and "identifying options" for the sale of "rights, interests and assets".
Regional carrier Flybe fell into bankruptcy for the second time in three years on January 28, with all flights grounded.
It has been operating 10 routes from Belfast City Airport.
There was speculation that airline groups Lufthansa and Air France-KLM were in talks with the administrators to buy the airline, which held lucrative take-off and landing slots at Heathrow Airport.
David Pike, managing director at Interpath and joint administrator of Flybe, said: "Over the past two-and-a-half weeks, we've held intensive discussions with a number of operators with a view to rescuing the airline and preserving the value in its assets.
"Unfortunately, there was a challenging set of circumstances at play, including the use-it-or-lose-it rules related to slots, complexities with European recognition of a potential Temporary Operating Licence and the high costs associated with preserving the company's operating platform, which meant there was a limited window in which a clear path forward could be set.
"Furthermore, it was clear from the outset that there was only a limited number of parties who had the necessary strategic fit and who could navigate the complexities of such a transaction to get a deal over the line. We thank those parties for their engagement.
"However, it is with regret that discussions have now been brought to a close without a deal being agreed."
Interpath confirmed that "a further 25 employees have been made redundant with immediate effect".
On January 28, it said 277 of Flybe's 321 staff would be made redundant.
Flybe was first pushed into administration in March 2020 with the loss of 2,400 jobs as the Covid-19 pandemic destroyed large parts of the travel market.
Before that, it had flown more UK domestic routes between airports outside London than any other airline.
Its business and assets were purchased in April 2021 by Thyme Opco, linked to US hedge fund Cyrus Capital.
Flights resumed 12 months later, with the airline based at Birmingham Airport.