MONTREAL, CANADAWilliam Walsh, the Director-General of the International Air Transport Association (IATA) involved in the dispute between Airbus and Qatar Airways on Tuesday.

Walsh said Airbus' decision to revoke an aircraft contract was a new and worrying development. The IATA director quoted that suppliers should not exploit market strength.

"I would hate to think that one of the suppliers is taking advantage of their current market strength to exploit their position, and that is something we are watching very closely," Walsh told reporters when asked about the issue during a press conference.

Qatar Airways sued Airbus in a London court for more than $600 million in compensation over the painting erosion on its Airbus A350 jets. The Qatari carrier refuses to take delivery of more of those jets until the problem is fixed. The airline also asks the London court to stop the delivery of Airbus' A350 jetliners.

Qatar civil aviation regulator grounded 21 planes out of 53 A350s operated by Qatar Airways over safety concerns.

Airbus insists the problem is technical and doesn't pose a safety risk. Last week, the European planemaker brought the dispute to another level by revoking a separate order for 50 A321neo.