MSC Cruises plans to order four ships in a new class, meaning it will have 11 vessels under development through 2026.
The line last week signed a letter of intent for the ships with the STX France shipyard at the Elysee Palace in Paris, with French President Francois Hollande in attendance.
The new vessels would each carry 5,400 passengers at double occupancy and be over 200,000 gross tons, making them similar in size to Royal Caribbean International's Oasis class, currently the largest in the world.
The ships will be fueled by liquid natural gas (LNG).
The new ships' class will be called World, and they will be built to sail in all seasons and all regions, an announcement said. The first of the World vessels would be due in 2022.
It marks the third class of ship that MSC has under development. The brand had previously announced the Meraviglia and the Seaside classes. The first of each of those classes are due next year.
With the four additional vessels, MSC will have nearly a dozen ships under development with a value of $10.2 billion. It valued the four World ships at $4.5 billion.
"Our long-standing focus on innovation will make the new prototype quite unlike anything currently existing in the cruise industry," MSC executive chairman Pierfrancesco Vago said.
He said the ships will have a futuristic design that will make them "a truly unique place to be at sea, whilst maximizing the open-air space available to guests."
The letter of intent underscores MSC's ability to compete financially with its biggest competitors, including Carnival Corp., which has 16 ships scheduled to be delivered between now and 2020.
MSC's parent company, Mediterranean Shipping Co, reported revenue of $28.2 billion in 2015, but it is privately held so the figures are not verified in public documents, and it is not known how much of that revenue drops to the bottom line. Carnival had revenue of $15.7 billion last year and net income of $1.76 billion.
The MSC ships are the second to be commissioned with LNG engines, signaling an expansion of the technology, which produces fewer carbon emissions and other pollutants than diesel fuel.
Carnival was the first to order ships with the pioneering LNG capability: two ships each for Costa Cruises and AIDA Cruises, starting in 2019.