(Boeing story updated with share price movement.)NEW YORK ( TheStreet) -- Turkish Airlines has completed an order of 20 next-generation 737 planes with Boeing ( BA) for $1.6 billion. The order includes 10 737-800s and 10 737-900ER airplanes and was previously posted to Boeing's orders and deliveries site as an unidentified customer. All of the new next-generation 737 planes will be fitted with the latest 737 Boeing Sky Interior, based on the cabin design of the 787 Dreamliner. Turkish Airlines currently operates a fleet of 66 Boeing airplanes, including 58 next-generation 737s. Boeing stock is down 0.7%, or 45 cents, at $67.50 in late morning trading. -- Reported by Andrea Tse in New York Follow TheStreet.com on Twitter and become a fan on Facebook.