Cruise operator Carnival has placed an order for a massive 141,000-ton, 3,611-passenger cruise ship, set to be the largest in its P&O Cruises fleet.The firm announced on Wednesday that it has contracted with Italian shipbuilder Fincantieri to construct the as-yet-unnamed ship. It is scheduled to enter the service in March 2015 and has been labelled as the "largest cruise ship built specifically for the British market."The all-in cost for the vessel is around €155,000 per lower berth."The UK continues to be a key growth market for Carnival and innovative vessels such as this new P&O Cruises ship - targeted specifically to British clientele - underscore our commitment to expanding this important cruise region," said company chairman and chief executive officer Micky Arison.The contract marks the eighth ship on order for Carnival, and the first ship deliver for 2015, in line with its strategy to build two to three ships per year.---BC