Europe's third-largest budget carrier by passenger numbers, which on Wednesday postponed 16 aircraft deliveries from Boeing and Airbus, raised its capacity by 37 percent in 2018 from 2017.

"The key priority going forward is returning to profitability through a series of measures, including an extensive cost reduction program, an optimised route portfolio and sale of aircraft," it said in a statement on Thursday.

Norwegian Air's fourth-quarter result plunged to a loss of 3 billion Norwegian crowns (£271.5 million) from a deficit of 713 million a year ago. The company had warned of a loss on Jan. 29.

The airline has shaken up long-haul rivals by offering cut-price transatlantic fares, but its rapid expansion has left it with hefty losses and high debts, leading it to shift recently to focus on bolstering its finances.

When IAG, British Airways' parent company, last month abandoned its attempt to buy the firm, Norwegian announced plans to raise cash from shareholders in the coming weeks.

(This story corrects spelling in headline)

(Editing by Gwladys Fouche)

By Terje Solsvik