NEW YORK (Reuters) — Carnival Corp & Plc, the world's largest cruise ship operator, said it ordered a new ship from Italian shipbuilder Fincantieri for about $738 million.

The 3,690-passenger ship is scheduled to enter service in the spring of 2012 as part of the Carnival Cruise Lines brand, Carnival said in a release. The ship will be built at Fincantieri's Monfalcone yard.

The ship, which will be the third in Carnival's Dream class of ships, will feature an aqua park with a 300-foot water slide, a live entertainment venue and a 23,750-square foot spa.

Carnival took delivery of its first Carnival Dream cruise ship in September and a second ship, the Carnival Magic, is slated to enter service in May 2011.

Miami-based Carnival, which has not ordered a new ship since December 2007, told analysts last month that a new ship order could be announced by the end of this year, Stifel Nicolaus analyst Steven Wieczynski wrote in a note.

"Shipyards are also becoming more aggressive on pricing due to their deteriorating backlogs," Wieczynski, who has a "buy" on the stock, wrote: "We believe CCL could announce more orders in early-2010."

Shares of Carnival rose 31 cents, or about one percent, to $32.34 in mid-morning trading on the New York Stock Exchange.

Rival Royal Caribbean Ltd rose 10 cents, or 0.4 percent to $24.67.

Royal Caribbean recently took delivery of the world's largest cruise ship, the Oasis of the Seas.