Viking Ocean Cruises and Fincantieri have signed an agreement for the construction of two additional cruise ships, said the yard in a prepared statement.

The new units, like the four sister ships which Viking has already ordered, will become part of Viking’s fleet in mid-2018 and at the end of 2020.

The first ship was delivered in early 2015; the second and third ships are scheduled for delivery in 2016 and 2017, respectively. Technical and financial conditions are still being defined for the fourth ship option.