Airbus and Qatar Airways were once the closest of partners.

But now they face a deepening legal rift.

The European jetmaker says it's revoking an order for 50 planes placed by the mideast airline.

That as Qatar demands compensation for other jets which it says are flawed.

The airline has stopped flying 21 of its A350 long-haul planes after finding peeling paint, cracked window frames and other issues.

It wants over $600 million to make up for the problems, and another $4 million for every day the grounding drags on.

Airbus concedes there's an issue, but is furious at any suggestion of a safety concern.

It says says the airline has leant on its local aviation regulator to order a grounding in a bid to secure compensation.

European regulators say they have found no safety issues with the planes.

Other airlines have seen similar problems with their A350s, but have not been ordered to keep them on the ground.

Now Qatar is seeking a legal order to stop Airbus delivering any more of the jets.

The planemaker says it will deny every aspect of Qatar's complaint.