• Highland Airways has run into financial difficulties
Highland Airways, based in Inverness, said it should know by Sunday if it has secured funding to guarantee its future.
The airline stopped taking online bookings and was only accepting on-the-day bookings until last night.
Bookings will now be accepted for all flights up to Sunday but seats on flights beyond that cannot be reserved.
An airline spokesman said: "It is hoped that, at that stage, we will be close to knowing whether the long-term future has been secured, and full functionality can then be restored."
The airline connects the inner and outer Hebridean islands to the mainland and also operates flights between Anglesey and Cardiff.
Some of Highland Airways flights are publicly subsidised through a Government scheme for people in remote areas.
The spokesman said: "It is known that the company has been facing difficult trading, most recently exacerbated by the severe winter, and resultant reduced flying and reduced income.
"The board has been seeking new investment and has been in discussion with several parties.
"Highland Airways appreciates all the messages of support it has been receiving, and requests its passengers' indulgence and patience, whilst we work through this difficult period."
The airline was founded as Air Alba in 1991, initially carrying oil workers and delivering newspapers.
According to its website, around 20,000 passengers a year use the company in Scotland.