SAN FRANCISCO, May 8 (Xinhua) -- U.S. top aircraft manufacturer Boeing Co. announced Tuesday that it has completed a new order to sell four more 777 airplanes to the largest German airline Lufthansa Group to modernize its fleet with newer widebody jets.

Under the 1.4-billion-U.S.-dollar deal, Swiss International Air Lines (SWISS), the national carrier of Switzerland and a member of the Lufthansa Group, will get two more Boeing 777-300ER extended-range airplanes.

SWISS currently has ten 777-300ER jets, which serve as the backbone of its long-haul fleet, and the additional airplanes will allow the company to further expand its network.

The 777-300ER has a seating capacity of up to 386 passengers in a three-class configuration and can fly a maximum range of 14,685 km.

The other two 777 Freighters will go to Lufthansa Cargo, one of the world's leading air freight carriers that serves nearly 300 destinations.

The 777 Freighter is the industry's largest and longest range twin-engine cargo jet, which can fly about 9,100 kilometers with a payload of 102,000 tons.

"The order for the new long-haul aircraft highlights the strategy of Lufthansa Group to predominantly allocate the growth within its multi-hub system where cost and quality offer the best conditions for profitable investments," the Lufthansa Group said in a statement.

The Group has earlier announced an order for up to 16 Boeing and Airbus aircraft at a cost of 2.1 billion euros (about 2.49 billion U.S. dollars), with deliveries scheduled for 2022.

The Lufthansa Group is the overarching name for Lufthansa, with its subsidiaries including Austrian Airlines, Swiss International Air Lines, Brussels Airlines, Eurowings, and Germanwings.

It is the largest airline in Europe both in terms of fleet size and passengers carried in 2017.