(Corrects the 3rd para to show that the firm is leasing the planes)
OSLO, Feb 13 (Reuters) - Norwegian Air has signed a letter of intent that will add four more Boeing Dreamliners to its long-haul fleet, boosting the total to 14, the low-cost airline said on Thursday.
The new planes, a stretched version known as 787-9, will be delivered in 2017 and 2018.
Norwegian said it would lease the new planes. (Reporting by Terje Solsvik, editing by Gwladys Fouche)