Pilots' leaders have raised fears of job losses after the parent company of British Airways announced it was ending its 12-year agreement with a cargo company.
IAG said it will end its agreement with Global Supply Systems (GSS), under which it has leased three freighter aircraft, from the end of April.
Steve Gunning, chief executive of IAG Cargo, said: " We have reviewed our long-haul freighter programme following the merger of British Airways and Iberia freight businesses to create IAG Cargo.
"The review took account of the growing cargo capacity available to us from our passenger fleet as well as the outlook for the air freight industry overall and we have made the strategic decision to significantly revise our long-haul freighter programme. I would also add that we greatly value the support we have received from GSS over the years."
GSS chief executive Rod Lynch said: " Although we are sorry to see the relationship end, we understand IAG Cargo's decision and will now direct GSS towards new opportunities."
The British Airline Pilots Association (Balpa) raised concerns for the jobs of 95 UK-based pilots.
General secretary Jim McAuslan said: "UK pilots are dismayed that IAG, a successful airline group predicted to make operating profits of more than £1 billion this year, is putting quality UK jobs at risk by terminating a successful UK-based cargo partnership.
"We will be working with GSS to support the workforce through this very difficult period and to minimise the impact of this disappointing decision by IAG."
An IAG Cargo spokesman added: " Current air cargo market conditions mean that operating freighters is not the most effective way to manage our cargo business. Many other cargo operators have ceased or reduced their freighter operations."