The revelation follows the formation of what a statement describes as “strategic partnerships” with Italian shipbuilding conglomerate Fincantieri and German compatriot Meyer Werft.

Carnival, which is headquartered in Miami, said the former will develop and construct five units at facilities in the cities of Monfalcone and Marghera.

The German shipbuilder will tackle the other four at shipyards located in Turku and Papenburg, the owner added in the announcement.

Carnival also pointed out that the initiative, which will begin in 2019, may involve further orders since the contracts include options, though the total was not specified.

“The shipbuilding agreements, which include options for additional ship builds in the coming years, are subject to several conditions, including satisfactory financing,” it said.

Carnival noted that the units will be among the “most efficient” it has ever built. Upon delivery, it plans to deploy them in both established and burgeoning markets.

“The new ships are expected to serve established cruise markets in North America and Europe, as well as newer markets, including China,” the operator explained.

In a statement the chief executive of Fincantieri, Giuseppe Bono, argued that the agreement with Carnival is a testament to his company’s “readiness and flexibility in interpreting the demands” of clients like Carnival, which is a repeat customer.

He added: “This agreement is the best reward for our hard work over all these years, and in fact, our organizational, design and production skills have allowed us to consolidate our market leadership, confirming us at the top of such an exclusive and complex industry.”

Carnival also reminded investors that, under its current “enhancement” strategy, it will have added two new vessels to its stable in 2015 and intends to offload four.

The owner declined to comment when asked about cost, which is difficult to predict since prices are dependent on so many different bells and whistles and vary greatly.

A spokesman did, however, mention that the Britannia might serve as a solid point of reference when pressed about how much was spent on similar projects.

According to a Wikipedia profile the 3,650-berth cruiseship, which was built by Fincantieri and joined P&O Cruises’ armada in 2015, cost more than GBP 470m ($702m). This suggests that Carnival’s newbuilding initiative could top $6bn.

The Italian shipbuilder has constructed more than a dozen vessels for the owner over the last ten years. Based on data from the Clarksons Shipping Intelligence Network portal, the average cost of these units was approximately $617m.