Italian shipbuilder Fincantieri has added to its orderbook in a €300m ($332m) deal with French line Ponant.
The company has contracted two 230-passenger luxury expedition cruise vessels, with one option attached.
The order is subject to the finalisation of technical and financial conditions.
The yard group has built four ships for Ponant before, delivered in 2010, 2011, 2013 and 2015.
And its Norwegian subsidiary Vard has handed over four Ponant Explorers-type ships in 2018 and this year, with two more to come in 2020.
Vard will also deliver Ponant's first hybrid electric polar exploration vessel powered with LNG in 2021.
The new 11,000-gt units, with battery packs, are due from Vard in 2022 and represent an evolution of the Ponant Explorers class.
They will be operated in the South Pacific under the Paul Gauguin Cruises brand.
Ponant CEO Jean Emmanuel Sauvee said: "For the first time in the world of cruising, these two new vessels will cut their engines and cease all emissions each day during each stop, for nearly ten hours per day.
"Small-capacity ships at the cutting edge of technology and environmental preservation: this project fully matches our philosophy of sustainable tourism".
