Norwegian is to lease two new Boeing 787-9 Dreamliners to be delivered in spring 2018.
The European budget carrier’s long-haul fleet will consist of 42 Dreamliners by 2020 with the additional aircraft.
The move came the day after the airline confirmed the start of low cost transatlantic flights between Gatwick and Las Vegas from October.
Norwegian currently operates eight 787-8s and two 787-9 Dreamliners.
Chief executive Bjørn Kjos said: “In order to offer customers more routes and make our intercontinental operation even more competitive, we need more brand new, cost-efficient aircraft.
“Our intercontinental operation is crucial to the company’s global growth and the creation of new jobs. The Dreamliner is a great airplane with high passenger comfort, long range, low fuel burn and reduced emissions.”
Norwegian also exercised purchase options for eight of 100 new generation, longer range Boeing 737 MAX8 aircraft.
The airline is the European launch customer for the short- to medium-haul aircraft with longer range, enabling intercontinental flights.