The number of passengers flown by Icelandic low-cost transatlantic challenger Wow Air grew by two thirds last year.

The 69% rise to 2.8 million passengers came on the back of an 80% capacity lift and it projects a further 900,000 carryings in 2018.

The airline’s load factor for 2017 was pegged at 80%, the same as the previous year.

The carrier’s fleet will expand to a total of 24 aircraft by the end of 2018 as it extends destinations served in North America, with the introduction of seven new aircraft, including two Airbus A321ceo, one Airbus A321neo and four widebody Airbus A330-300neo.

Wow Air is only the second airline globally to introduce the A330-300neo, using new engine, wing and electronic systems to provide enhanced operating efficiency and passenger comfort.

The airline offers UK departures to its hub in Iceland from Gatwick and Edinburgh, with Stansted being introduced in April.

The flights will connect up with new transatlantic routes to Cleveland from May 3, Cincinnati from May 9, Detroit from April 25, Dallas from May 23 and St Louis from May 17.

The carrier has expanded from its launch in 2011 to cover 38 destinations across Europe, the US and Canada.

Founder and CEO Skúli Mogensen said: “2017 was marked by rapid growth and investments throughout our company and fleet.

“We have never been better equipped to continue our future growth and we expect to transfer 3.7 million passengers in the year 2018.

“I look forward to all the exciting developments that are on the horizon, including upcoming new destinations and aircraft, which will ultimately make the Wow journey even more pleasurable for our passengers.”