Highland Airways operates in Scotland and Wales
Highland Airways has refused to comment on its future involvement in a service between Cardiff and Anglesey in Wales.
The airline has been in discussions with a potential investor after hitting financial troubles made worse by severe weather affecting flights.
Its contract with the Welsh Assembly Government ends in May and the route has been put out to tender.
Highland Airways' commercial director, Basil O'Fee, said he would prefer not to comment at this stage.
The Welsh Assembly Government announced last Thursday that the contract was to be subject to a fresh tendering process after an initial effort to appoint a contractor was unsuccessful.
In a statement, Deputy First Minister Ieuan Wyn Jones said it was an "essential link" between north and south Wales and had exceeded the government's expectations.
He said: "The current contract comes to an end this May and we recently re-tendered the service.
"Unfortunately the tender process was not successful and we did not receive any bids that complied with the requirements of this particular tender.
Mr Jones added: "We are currently considering the options to deliver the service on a short-term basis from the end of May, with a view to starting a new tender process to appoint a suitable airline for a longer-term contract."
Mr O'Fee said he did not wish to make any comment at this stage on the Welsh route, or the Inverness-based airline's current situation.
In February, the company's board members said they were "cautiously optimistic" about its future.
The airline signed an agreement with a potential investor to help push ahead with negotiations.
Highland Airways said at the time it was only accepting bookings on all scheduled flights until the end of March.
The company also runs air services between Stornoway and Benbecula in the Outer Hebrides and also Oban and the Inner Hebrides.
Other activities include aerial work, newspaper delivery to some Scottish islands, corporate staff shuttles and air charter.