Finnish shipyard STX said TUI Cruises has ordered a ship for delivery in spring 2015.
The ship will be 99,300 gross tons and carry 2,500 passengers, STX said.
STX is already building a ship for TUI that will go into service in the spring of 2014.
"Manning on this project will increase significantly during the coming months to reach the maximum level before summer next year", Jari Anttila, chief operating officer of STX Finland, said in a statement.
Richard Vogel, CEO of TUI Cruises, said the new order will continue the growth of its fleet.
"We have been extremely busy with the planning over the past two years, but now things are really starting to move," Vogel said.
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