Costa Mediterranea officially joined the Costa fleet in May 2003.
The official ceremony marking the change of flag, after the signing of the papers, was held at the Finnish shipyard where the vessel was constructed.
Costa chairman Pier Luigi Foschi said:
"The delivery of Costa Mediterranea is another stepping stone in our policy of investment in the development of our fleet and our Company. This ship and those to come will allow us, through the quality of our cruise offer, to retain our European leadership and introduce a large number of vacationers to the pleasure of cruise holidays.
"We are especially proud to see the Italian flag on the Costa Mediterranea which, thanks to her interiors dedicated to 17th and 18th Century palazzi and to the many magnificent works of art displayed on board, will take Italian art and hospitality across the seas of the world."
Following the handover, Costa Mediterranea, built at a cost of 375 million euros, departed Helsinki on a European tour to Hamburg, Dover, Le Havre and Barcelona.
The construction of Costa Mediterranea, sister of present flagship Atlantica, began in January 2001. She is 86,000-tons and has a maximum capacity of 2,680 passengers accommodated in 1,057 cabins, 70 per cent with oceanview.
Costa Mediterranea stands out on account of her surprising, tasteful, elegantly Italian style. The interiors are particularly refined, inspired by noble Italian 17th and 18th Century palazzi. Piazza Casanova, which evokes the atmosphere of a typical Venetian living room, is based on Palazzo Albrizzi in Venice; the same Italian seaport provides the inspiration for the Casino Canal Grande.
The most surprising and spectacular area of the Costa Mediterranea is the main lobby, where it is possible to admire theatrical scenery stretching all the way to the skylight with a series of sculptures intended as a tribute to Italian culture and dance.