Carnival Cruise Lines has already decided it will return the Carnival Liberty to Europe in summer 2006. The Liberty is offering the line's first-ever cruises in Europe this summer, upon its delivery in July. Carnival said demand for those Mediterranean cruises was so strong, it decided to return with a full season next year. In 2006, the Liberty will operate 15 12-day cruises roundtrip from Civitavecchia ( Rome) from May 7 to Oct. 22. Ports of call include Naples, Dubrovnik, Venice (for two nights), Messina, Barcelona, Cannes and Livorno. Prior to and following that program, the ship will operate a 14- and 16-day transatlantic cruise to and from Ft.Lauderdale, where it will winter. Carnival will begin accepting reservations for the 2006 Med cruises on May 25.