DOHA, QATARQatari flag carrier Qatar Airways grounded one more Airbus A350 aircraft after the national civil aviation authority of the Gulf country canceled the aircraft's Airworthiness Review Certificate.

Qatar Airways and Airbus have been in a severe dispute for a while over the deteriorating surface painting of the airline's Airbus A350 jets.

With the latest grounding, the total number of the carrier's grounded Airbus A350s became 2.

"This decision has been taken by our regulator as all of these aircraft have developed damage as a result of the A350 Accelerated Surface Degradation Condition, which is beyond the tolerance limits set by Airbus," the airline said in a statement on Monday.

"The regulator will not allow these aircraft to return to service until a full and conclusive root cause analysis has been completed, the impact on continuing airworthiness has been established and a solution been found to permanently correct the root cause and repair the damage".

The dispute has been extended into a legal case in a division of London's High Court.

In January, Airbus revoked a deal with Qatar Airways for 50 A321neos.

Earlier this month, Qatar Airways placed an order for 50 Boeing 737 MAX 10 jets, giving the American aircraft manufacturer an advantage over its rival, Airbus.

"Qatar Airways will continue its legal action to seek an order that requires Airbus to fully, properly and transparently investigate the A350 Accelerated Surface Degradation, to establish the conclusive and full root cause of an important condition which is degrading the surface of the aircraft beneath the paint," the airline said.

Qatar Airways noticed the painting problems last year when it sent one of its A350 aircraft to be repainted with World Cup livery.

Airbus recognized the issue, performed analyses, and proposed solutions but insisted that the defects did not result in a safety issue.