Boeing and Qatar Airways have announced an order for 30 Boeing 787-9 Dreamliners and 10 Boeing 777-300ERs, valued at $11.7 billion at list prices.

The airline also signed a Letter of Intent for up to 60 737 MAX 8s, valued at $6.9 billion at list prices.

Today's announcement builds on Qatar Airways' current fleet of 84 Boeing aircraft, a combination of 787s and 777s, all delivered over the last nine years. With this new order, Qatar Airways increases its firm order backlog of Boeing widebody airplanes from 65 to 105, including 60 777Xs.

The announcement was attended by the State of Qatar's Minister of Finance, His Excellency Ali Shareef Al Emadi, U.S. Deputy Secretary of State Tony Blinken and the Ambassador of Qatar, His Excellency Mohammed Jaham Al-Kuwari.

The 777-300ER is the most reliable twin-aisle airplane flying today and is considered to be the flagship of the world's elite airlines. It has the highest schedule reliability of any twin-aisle airplane at 99.5 percent – the airplane is on time, nearly all the time.

The 787-9 Dreamliner is the second member of the super-efficient, passenger-pleasing 787 family. The 787-9, a stretch of the 787-8, can fly 290 passengers 7,635 nautical miles (14,140 km) in addition to more cargo, allowing airlines the ability to grow routes first opened by the 787-8.