The Boeing Company (NYSE:BA ) said Wednesday that it has finalized a deal worth $56 billion for 150 777X planes with Dubai-based Emirates, which locked in the single largest order for Boeing at the Dubai Airshow in November.

Boeing said that Emirates placed an order for 115 twin-engined, twin-aisle 777-9X aircraft and one for 35 planes of the 777-8X variety, along with purchasing rights for another 50 airplanes. If the rights are utilized, then Boeing expects the order value to be worth $75 billion at list prices. Boeing had received a total of seven orders for its 777 jets by June-end and expects to deliver 48 planes of the same model type in 2014. Boeing's 777X jetliner, which can reportedly carry up to 550 passengers, is expected to compete with the Airbus A380.

"With the order for 150 777Xs, Emirates now has 208 Boeing 777s pending delivery, creating and securing jobs across the supply chain,” Tim Clark, president of Emirates, said according to a statement released Wednesday by Boeing, adding: “The 777X will offer us operational flexibility in terms of range, more passenger capacity and fuel efficiency, and we look forward to inducting them into our fleet from 2020.”

The Chicago-based Boeing will deliver six 777 jets to Emirates this year, while the airplane manufacturer plans to introduce improvements to its $320 million 777X model, including a high-efficiency composite wing, which will have a longer span and a GE-9X engine, reportedly the most advanced engine in a commercial plane. The 777-9X, which Emirates has ordered in bulk, reportedly has an engine that is 12 percent more efficient than its competitors in the segment, according to Boeing.

“I'm confident the 777X – with its new engines and all-new composite wing design – will bring superior value in terms of performance, efficiency and reliability to Emirates,” Ray Conner, president and CEO of Boeing Commercial Airplanes, said, according to the statement, noting that Emirates is now the largest launch customer for the 777X.

Last month, Emirates cancelled an order for 70 A350 jets from Europe's Airbus (EPA:AIR), which was a deal worth $16 billion at 2007 list prices.