Qatar Airways decided to double its commitment for the Boeing 777-9X as it has an expanded requirement for the big twinjet for its leasing arm.

It also says the move comes as a result of its growing confidence in the product that Boeing will offer.

The Doha-based airline has confirmed the letter of intent it disclosed at the Dubai air show in November 2013 for 50 of the General Electric GE9X-powered 777-9X. It has added purchase rights for another 50.

“This totals an order for 100 777X aircraft, which will become the backbone of the Qatar Airways fleet, and represents the largest single aircraft order in our history,” says Qatar Airways chief executive Akbar Al Baker.

Boeing values the order and purchase rights at $37.7 billion.

The order commitment has been doubled due to a combination of factors, says Al Baker.

“What changed is the confidence we have in Boeing to be able to make absolute top-class aircraft. They have a track record of what they’ve done with the 777-300ER, which exceeded all its performance expectations, and we have confidence that the 777X will be the same,” says Al Baker.

The requirements of the airline’s new leasing arm have also come into play: “Qatar Airways will also be in the aircraft leasing business soon so we will have not only aircraft requirement for our fleet but also for our leasing arm.”

Source: Cirium Dashboard