All flybmi flights to and from Aberdeen have been cancelled after the airline filed for administration.
However, sister carrier Loganair said it was unaffected and its flights would continue as normal.
The Scotsman understands Loganair may announce shortly it is taking over some of flybmi’s routes.
Both airlines are owned by Airline Investments Limited, which was previously based in Aberdeen.
The immediate cancellation of all flybmi flights, including the three served by Aberdeen International, was announced on Saturday night.
The airline blamed Brexit for its collapse and in a statement said: “We sincerely regret that this course of action has become the only option open to us, but the challenges, particularly those created by Brexit, have proven to be insurmountable.”
Flybmi had flights between Aberdeen and Esbjerg in Denmark, Oslo in Norway and Bristol.
On Sunday, the 11:05am flight to Oslo and the 3:35pm flight to Bristol have been cancelled.
Two flights due to arrive in Aberdeen from Oslo and Bristol are also cancelled.
Flybmi operated 17 aircraft on routes between 25 European cities, with the East Midlands-based firm employing 376 people in the UK, Belgium, Germany and Sweden.
Customers who had booked flights with flybmi are advised to contact their credit or debit card provider, or their travel agent, to get a refund.
A flybmi spokesman said: “It is with a heavy heart that we have made this unavoidable announcement today.
“The airline has faced several difficulties, including recent spikes in fuel and carbon costs, the latter arising from the EU’s recent decision to exclude UK airlines from full participation in the Emissions Trading Scheme.
“These issues have undermined efforts to move the airline into profit.
“Current trading and future prospects have also been seriously affected by the uncertainty created by the Brexit process, which has led to our inability to secure valuable flying contracts in Europe and lack of confidence around bmi’s ability to continue flying between destinations in Europe.
“Additionally, our situation mirrors wider difficulties in the regional airline industry which have been well documented.
“Against this background, it has become impossible for the airline’s shareholders to continue their extensive programme of funding into the business, despite investment totalling over £40 million in the last six years.
“Our employees have worked extremely hard over the last few years and we would like to thank them for their dedication to the company, as well as all our loyal customers who have flown with us over the last six years.”
A Loganair spokesman said: “It’s business as usual, with all flights operating tomorrow and thereafter for Loganair.
“We have done a lot of work to put Loganair onto a sound financial footing in last 12 months despite the wider issues in the sector.”
The company added: “The two airlines are separate businesses, operating separate aircraft fleets on their own distinct route networks.
“As such, the closure of bmi Regional – which flew Embraer Regional Jet aircraft on routes throughout 12 European countries – has no impact on Loganair’s continued operation, which predominantly uses turboprop aircraft on routes within the UK and in particular to, from and within the Scottish Highlands and Islands.
“The same challenges that have led to bmi Regional ceasing operations, including uncertainty around intra-European traffic rights post-Brexit, do not impact Loganair’s business.”
Loganair managing director Jonathan Hinkles said: “Loganair expects to return to profit in the current financial year, is carrying record passenger numbers on many of its routes and is in a strong financial position.
“We are actively working on options to offer employment to a number of bmi Regional staff members, whilst at the same time monitoring developments elsewhere in the UK regional airline sector which could present opportunities for Loganair.”
Rory Boland, Which? travel editor, said: “This is terrible news for flybmi passengers, who will be seeking urgent advice on what steps to take.
“Some customers have claimed that tickets were being sold in the hours before the airline went bust, knowing full well those tickets would never be honoured, and passengers will rightly be outraged if this is proved to be the case.
“As all future flights have been cancelled, flybmi customers should explore their options for refunds.
“If you purchased your flight as part of a package, you should be ATOL protected, which means you should get a refund.
“However, if you didn’t book as part of a package, you may be able to claim the cost back through your travel insurance or credit card issuer, but it depends on your circumstances.”
Brian Strutton, general secretary of the British Air Line Pilots Association (Balpa), said: “The collapse of flybmi is devastating news for all employees.
“Regrettably, Balpa had no warning or any information from the company.
“Our immediate steps will be to support flybmi pilots and explore with the directors and administrators whether their jobs can be saved.”
Tim Alderslade, Chief Executive of Airlines UK, which represents 13 UK carriers, said: “Today’s announcement demonstrates once again the ferociously competitive environment airlines operate in.
“It should give Government – and other parts of the industry who relentlessly champion passenger growth but too frequently neglect the challenges carriers face – pause for thought about the costs they are asking airlines to absorb and to what extent this is sustainable into the future.”