The bmi airline has confirmed 19 return flights between Inverness and Heathrow will be cancelled from next Wednesday.
Airline bmi has cancelled flights on other routes
The company said it was doing what many airlines do in adjusting the schedule in response to lower demand over the winter period.
However, Inverness Chamber of Commerce said the changes were a concern and had come at short notice.
Starting with a flight on 7 November, cancellations will run through to 6 February.
Highlands and Islands Airports Limited (HIAL) said other airlines regularly make adjustments to their schedules.
Winter cancellations by bmi also affect its flights between Heathrow and Venice, Palma and Lyon.
The airline said in some cases it could use smaller aircraft in response to lower numbers of passengers, but in others it had no option but to cancel.
A spokesman said: "The latter has been the case on certain days on services between Heathrow and Inverness where there has been insufficient passenger demand to sustain the service on the specific dates affected.
"Passengers affected by the changes have been notified and been offered either a full refund or alternative flights."
Donald Shaw, president of Inverness Chamber of Commerce, said it was vital that peripheral areas such as Inverness had guaranteed links to the UK capital.
He said: "It is indeed causing concern because this has come at short notice.
"These links with the main hub are essential, particularly for the Highlands.
"At the end of the day airlines are a business, but they must have some moral responsibility for the communities they serve."