A leading freight operator is pulling out of Kent International Airport, saying a rise in charges has made it too expensive to be based there.
Cargo flights make up the majority of Manston's business
Freight flights form the majority of business at the airport, in Manston.
MK Airlines has flown out of the airport since 1999 but is now moving its base to Ostend in Belgium.
The airline said it wanted to stay but could not afford to do so, but airport management said MK Airlines had enjoyed a very attractive deal for five years.
The charges for using the airport, which has recently been used for aid flights to Sudan, were increased in April.
MK Airlines said it flew 38,000 tonnes of cargo a year from Manston and airport managers told the BBC 'a substantial amount' of the airport's trade had come from the company.
MK Airlines spokesman Steve Anderson said: "As the first operator out of the airport we had a long-term agreement in place with the airport owners, which was only halfway through.
"But they decided they wanted to review the pricing mid-term and this represented very major increases.
"Quite honestly, we wanted to stay there but in this day and age money does talk and the sort of increases we were talking about are simply unsustainable."
Kent International Airport director Alistair Robertson said: "Our view was that MK have been operating since 1999 and they came in on what was a very attractive deal.
"We have given them excellent service and excellent value for money ever since.
"Clearly MK have made a decision based on commercial reality in relation to their business but regrettably we have to do the same.
"Talks are ongoing with other freight operators and we hope they will come to fruition sooner rather than later."