New Caribbean routes and Spanish domestic flights helped Norwegian Air push up January carryings by 9% to more than 1.7 million over the same month last year.
The low-cost carrier introduced new routes from the French Caribbean islands of Martinique and Guadeloupe to Baltimore/Washington, New York and Boston.
The services have been well received by customers in the Caribbean and the US, as well as Europeans connecting through New York, the airline said.
Norwegian has extended the season through to April on selected routes due to the positive response.
The overall load factor was up by 1.7 percentage points to 81.7% year-on-year.
The airline’s chief executive, Bjørn Kjos, said: “We are very pleased that we have attracted more passengers and achieved a higher load factor in a traditionally slower month.
“The growth is primarily due to international expansion, with domestic flights in Spain and the routes between the French Caribbean and the US East Coast.
“In addition, more passengers are choosing Norwegian on intercontinental routes.”
The airline’s fleet is being expanded this year with the addition of 17 Boeing 737-800s and four 787-9 Dreamliners. Seven older 737-800s will leave the fleet.
Norwegian will also take delivery of four Airbus A320neos that will be leased out.