Qatar Airways has agreed to purchase as many as 100 Boeing airplanes for up to $18.6bn, the companies jointly announced on Friday.
Qatar will buy 30 of the new-generation Boeing 787 and 10 Boeing 777, both widebody aircraft, for $11.7bn. Qatar Airways also signed a letter of intent to purchase up to 60 of the narrow-body Boeing 737 valued at about $6.9bn.
Qatar Airways chief executive Akbar Al-Baker said that the order was one of the largest in the country's history and would help meet growing demand for air travel.
Al-Baker acknowledged the decision to go with Boeing also was due to "ongoing issues" with Boeing rival Airbus.
Al-Baker in April publicly blasted Airbus over delays in deliveries of the single-aisle Airbus A320neo due to problems with its engine. In June, Qatar Airways cancelled an order for one of the planes.
"Boeing has started building airplanes before everybody else," al-Baker told a news conference in Washington attended by government officials from the US and Qatar.
"They make the best airplanes, even if their competitors will not like me saying this."
The contract for the 737 marks the first time Qatar Airways has ordered single-aisle planes from Boeing in more than 15 years, the companies said.
"Our partnership with Qatar Airways has grown and strengthened tremendously over the years and I look forward to the time when its fleet will feature an increasing number of both our single and twin-aisle airplanes," said Ray Conner, chief executive of Boeing's commercial airplane division.
The companies did not release a time-frame for deliveries.
The order for up to 100 jetliners helps fill out Boeing's order book in a year when sales have slowed sharply, and amid tough price competition with Airbus.
It is significantly larger than a deal for five Boeing 777-300ER aircraft worth $1.7bn that the carrier had been expected to place during Britain's Farnborough Airshow in July.
That announcement was postponed by the Qatari government in an effort to speed up US approval of its purchase of Boeing fighter jets, sources familiar with the situation said.
Boeing shares were down 0.8% at $133.40 in late morning trading on the New York Stock Exchange.