The news is in addition to the line’s plans to grow its ocean fleet to 16 ships with six new vessels between 2024 and 2027.

The contract between the Viking and Fincantieri subsidiary Vard Holdings Ltd includes an option for two extra vessels and is potentially worth around £410 million.

Delivery of the ships from one of Vard’s Norway-based shipyards is scheduled during the second quarters of 2021 and 2022.

The company added that the ships would be “advanced” and “designed to be among the most environmentally friendly” vessels in the cruise sector.

The ships’ hulls will be built by Vard in Romania.

In a statement, Vard said it and Viking had a common intention to enter into final contract to build the vessels by mid-2018.

Roy Reite, Vard’s chief executive and executive director, said: “It is our pleasure to work with Viking to develop a series of cruise vessels.

“The company is well known for its expansion in river cruises and ocean cruises. We are honoured to be chosen as their partner in this exciting partner and look forward to continuing the excellent cooperation with the Viking team.”