Europe’s third largest low-cost carrier cut underlying first quarter losses by £34 million or 400 million Norwegian krone (Nok).

However, pre-tax losses were deeper at 992 million Nok against 777 million Nok in the same three months a year earlier.

The airline said negative currency effects and losses from forward jet-fuel contracts amounted to a loss of 528 million Nok.

The load factor was up by two percentage points to 85%, in a quarter that is traditionally considered low season.

Year-on-year passenger carryings rose by 17% to 5.82 million from 4.96 million.

The strongest growth was at Gatwick, where the airline operates both long- and short-haul routes.

The growth at Spanish airports was described as “considerable” while passenger numbers also increased in the Nordic countries.

Chief executive Bjørn Kjos said: “The first quarter results show that we have an underlying profit improvement of 400 million Nok compared to the same quarter last year.

“Our load factor continues to be very high. The long-haul operations are becoming significantly more important.

“We also see growth in the Nordics and in Europe in general. We also see that the Scandinavian and European route networks both play an increasingly important role in our long-haul strategy, as many of our passengers connect from short haul to long haul and vice versa.

“An increasing number of business travellers choose to fly with Norwegian, and we have entered into agreements with several large corporations in the first quarter. This indicates that passengers appreciate a high quality product at a low price.”

The airline started long-haul routes between Paris and the US in the quarter and took delivery of five new Boeing 737-800s and one B787-9 Dreamliner. Norwegian will have 12 Dreamliners in operation by the end of 2016.

Klos said that Norwegian “is establishing and preparing for an organisational structure that will secure cost efficient international expansion and necessary traffic rights for the future”.

But the market in Norway is influenced by the slowdown in the economy and there is increased competition in the Danish market, he said.