The vessels will be larger, with 2,444 staterooms each, and delivery of these Meraviglia-Plus ships is scheduled for October 2019 and December 2020.
This means delivery of the last of the now four Meraviglia ships is scheduled nearly two years earlier than expected.
'Our long-standing cooperation with STX France and the continued growth of our business allows me today to confirm well ahead of time the existing options for two additional ships,' MSC Cruises executive chairman Pierfrancesco Vago said. 'The two Meraviglia-Plus vessels will be even larger and longer as well as richer in features and amenities,' he added.
Each has an additional 200 staterooms and a maximum capacity for nearly 6,300 passengers. Each will stretch 1,085 feet.
Among new features, the ships will sport a contemporary fine art museum.
The news came during the coin-laying ceremony for MSC Meraviglia, which will enter service in June 2017. Vago also announced the ship's christening will take place June 1 in Le Havre, and MSC Meraviglia's homeport will be Marseille.
Notable guests included Emmanual Macron, France’s minister of economy, industry and digital affairs, and Edouard Philippe, the mayor of Le Havre and a member of Parliament.
STX France president Laurent Castaing hailed the orders as extending a 'unique and remarkable partnership that we have built with MSC Cruises over the years.'