Viking Ocean Cruises is to further expand its fleet with an additional two new ships and options on two others.
The 930-passenger vessels are due to enter service in 2021 and 2022 and will bring the fleet up to eight ships.
Viking takes delivery of its fourth ship, Viking Sun, this autumn and a fifth, Viking Spirit, next year. A sixth 47,800-ton vessel is scheduled to enter service in 2019.
The new ships are to be built at the Fincantieri ship yard in Italy.
Viking Cruises chairman, Torstein Hagen, said: “We set out to bring the destination back to cruising, and the cruising public has responded.
“These additional ships are needed to meet the demand we are experiencing.”
Fincantieri chief executive, Giuseppe Bono, added: “The series – which began with the Viking Star prototype – reaches eight ships with these additional units, with the possibility to further grow thanks to the expansion plans of this dynamic cruise company.”