The aircraft manufacturer Airbus is being sued by its important customer Qatar Airways over problems with the A350 aircraft.
The company filed a lawsuit against Airbus with the Technology and Construction Department of the High Court in London on Monday, Qatar Airways said.
"Unfortunately, all of our attempts to find a constructive solution with Airbus in connection with the accelerated surface wear of the Airbus A350 aircraft have failed."
Qatar Airways is one of the most important Airbus customers and already has 53 A350 aircraft in its fleet.
Another 23 have been ordered.
However, the airline of the Arab Emirates of Qatar has taken a number of machines of the type out of operation due to problems with the surface coating of the machines and suspended the acceptance of further jets in June.
"The legal process was initiated to ensure that Airbus is now responding to our legitimate concerns without further delay," said the airline.
In the late evening, Airbus confirmed the receipt of a formal legal complaint.
The company is analyzing the content of the complaint, but wants to vigorously defend its own position.
Problems not relevant to security
Airbus program director Philippe Mhun recently emphasized that the problems were not relevant to safety.
This has also been confirmed by the European aviation authority EASA.
Airbus had announced that it would have the matter legally examined by an independent expert.
The dispute with Qatar Airways has been going on for over a year.
A metallic fabric that protects against lightning strikes lies between the fuselage and the exterior paintwork of the A350.
According to earlier data from Airbus, cracks in the paintwork or in this fabric appear on some aircraft of the type, depending on the operating conditions.