German's TUI Group and Royal Caribbean of the US are continuing to expand their TUI Cruises joint venture with a new order for LNG-powered vessels.
The companies have picked Fincantieri in Italy for the two-ship contract.
The vessels are due in 2024 and 2026 from the Monfalcone yard, but no financial details are being revealed.
The deal will grow the Mein Schiff fleet to nine ships by 2026.
"TUI Cruises is thus significantly developing its already strong and dynamic position in the German cruise market," it said.
The vessels will be 161,000 gt.
Giuseppe Bono, CEO of Fincantieri, said: “These will be the largest ships ever built in Italy.
"We at Fincantieri have once again demonstrated to offer to the market with the best equation of reliability and ability to innovate, pillars of the Made in Italy products and which identify Fincantieri in the world shipbuilding scenario.
"The project allows us to add TUI Cruises as a new and outstanding brand to our customer portfolio. Furthermore, it is also a cutting-edge reference to our products from a technological point of view.”
Wybcke Meier, CEO of TUI Cruises, added: “The decision to run the two additional newbuilds of the fleet planned for commissioning in 2024 and 2026 on low-emission liquefied natural gas is a logical continuation of our environmental strategy."
Earlier this month, Fincantieri-owned Vard Holdings clinched the contract to build a new vessel for another TUI company, Hapag-Lloyd Cruises.
The "luxury" expedition ship is the third in the shipping company's Hanseatic series - the first two of which Vard is also constructing.
No price has been revealed for the latest 16,000-gt addition, but it will be handed over in the second quarter of 2021 from Vard Langsten in Norway.
