Carnival Corporation has signed a multi-billion dollar contract with Meyer Werft to construct four cruise ships powered by liquefied natural gas (LNG), representing a major environmental breakthrough in the cruise industry.

The new vessels, which would be the first LNG-powered cruise ships, will feature a ‘green cruising’ design and offer the largest guest capacity in the world.

The contract is part of the strategic memorandums of agreements that Carnival signed with Meyer Werft and Fincantieri to build a total of nine new cruise ships over a four-year period between 2019 and 2022.

"These are exceptionally efficient ships with incredible cabins and public spaces."

Carnival Corporation CEO Arnold Donald said: "At a cost per berth in-line with our existing order book, these new ships will enhance the return profile of our fleet.

"These are exceptionally efficient ships with incredible cabins and public spaces, featuring a design inspired by Micky Arison and Michael Thamm and developed by our new-build teams."

Each vessel is more than 180,000gt, with over 5,000 lower berths to accommodate up to 6,600 guests.

Meyer Werft will construct two ships under this contract at its shipyard in Papenburg, Germany, which will be delivered to AIDA Cruises in 2019 and 2020.

The remaining vessels will be manufactured at Meyer Werft’s shipyard in Turku, Finland.

According to Carnival, this new order will strengthen the position of Costa Group, comprising AIDA Cruises and Costa Cruises, in the European cruise market.

Under the previously announced strategic memo of understanding, Fincantieri will initially build five ships at its shipyards in Monfalcone and Marghera, Italy. These agreements also include options for additional ships.