FILE PHOTO: Qatar Airways staff hold a Qatari flag in front of an Airbus A350-1000 at Hamad International Airport in Doha, Qatar, February 21, 2018. REUTERS/Naseem Zeitoon/File Photo

DUBAI (Reuters) - Qatar Airways said on Monday it was upgrading five of its Airbus AIR.PA A350 jets on order to the largest model, in a boost for the European planemaker's largest twin-engined jet.

The Gulf airline was the launch customer for both A350 models and said in February it could switch some of its existing order of A350-900s to the bigger A350-1000.

“Since taking delivery of the world’s first A350-1000 in February 2018, we have been extremely pleased with the aircraft’s performance, which has prompted us to update our original order,” Qatar Airways Chief Executive Akbar al-Baker said in a statement.

State-owned Qatar Airways has upgraded the order amid a political dispute in the Arab region that has forced the airline to increase operational costs by flying longer routes.

Qatar Airways has been banned from the airspace of Saudi Arabia, the United Arab Emirates, Egypt, and Bahrain since June 2017 as a result of those countries cutting ties with Qatar.

The upgraded order will come as a relief to Airbus, which is betting on the A350-1000 to contain any market pressure from rival Boeing BA.N which is developing its new model 777 twin-engined jet.

The A350-1000 is designed to seat 366 people and competes head-to-head with Boeing’s profitable 777. Airbus says the lightweight A350-1000 is 25 percent more efficient than the most popular current version of the 777, the 777-300ER.

Qatar Airways is the top A350 customer with 76 on order, which now includes 42 A350-1000s with a list price of $367 million. Airbus said that in Qatar Airways’ configuration, the A350-1000 features 44 more seats than the A350-900.