South Korean airline Korean Air has finalised an agreement to buy 20 Boeing 787 Dreamliner aircraft.

Comprising ten 787-10s and ten 787-9s, the deal was announced as part of the Paris Air Show last month and is valued at $6.3bn according to list prices.

Besides an agreement to lease ten additional 787-10 aircraft from Air Lease Corporation, Korean Air will quadruple its Dreamliner fleet due to the demand for the jet’s efficiency and passenger comforts.

The recent addition of the 787-10 to its long-haul fleet will complement Korean Air’s existing 787-9 and 777 aircraft.

As the largest member of the Dreamliner family, the 224ft-long 787-10 can accommodate up to 330 passengers in a standard two-class configuration, approximately 40 more than the 787-9 jet.

Powered by advanced technologies and a revolutionary design, the 787-10 operates at a reduced cost.

Korean Air chairman Walter Cho said: “As we continue to innovate our product offering, the 787 Dreamliner family will become the backbone of our mid-and long-haul fleet for many years to come.

“In addition to 25% improved fuel efficiency, the stretched 787-10 offers around 15% more space for passengers and cargo than our 787-9s, which will be critical to our long-term business goals.”

The airliner plans to commission the 787-10 on medium-range routes and continues to enhance the longer-range capabilities of the 787-9 Dreamliner on long-haul flights.

Boeing commercial sales and marketing senior vice-president Ihssane Mounir said: “With the 747-8, 777 and now the 787 Dreamliner family, Korean Air operates one of the most efficient and comprehensive widebody fleets in the world.”

Korean Air’s aerospace division is a key partner of Boeing on the latter’s 747-8 and 787 programmes.

It also supplies the Advanced Technology Winglet on the 737 MAX.