World Class 5 and 6 are scheduled to be delivered in 2029 and 2030 and once built will join a fleet featuring MSC World Europa, MSC World America, MSC World Asia and MSC World Atlantic. 

The latter two vessels are slated to enter service in 2026 and 2027 respectively. They are currently under construction. 

MSC said the World Class fleet "significantly outperforms" the International Maritime Organization’s Energy Efficiency Design Index and added the new ships would "continue to uphold the high energy efficiency standards set by their sister ships". 

The new vessels will have shore power plug-in connectivity to slash carbon emissions in port, the most advanced wastewater treatment systems and "a comprehensive range" of onboard energy-efficient equipment to optimise engine use and hotel energy needs to further reduce emissions, it added.

Pierfrancesco Vago, MSC Cruises executive chair, said: "The confirmation of the orders for the two new World Class ships marks a new milestone in our remarkable journey of shipbuilding in France and the continuation of our long-term industrial plan.  

"This milestone underscores our commitment to building some of the highest-performing ships in the world, creating a legacy of excellence and innovation in collaboration with the Chantiers de l’Atlantique – our long-term partner of more than 20 years." 

He added: "The highly successful World Class platform combines the very best in environmental technology with the latest advancements in guest experiences.”