Arison, who will keep his title as chairman of the board, has been CEO since 1979, before Carnival became a publicly traded company. Carnival was founded in 1972 by Ted Arison, Micky Arison's father.
Arnold Donald, who has served on Carnival's board for the past 12 years, will become the new CEO on July 3. Donald was CEO of Merisant Company, a producer of sweetener products that he founded, from 2000 to 2003. He also held multiple senior management roles at Monsanto.
"As chairman, I will still be working closely with Arnold to ensure a great future for all our stakeholders," Arison said in a statement.
This change in executive leadership comes at a time of declining revenues for Carnival. Second-quarter gross revenue, affected by discounts in cruise ticket pricing, decreased 3.1% over the same period the previous year. Nevertheless, declining fuel prices helped Carnival produce a U.S. GAAP net income of $14 million for the quarter.
Negative publicity following several incidents involving Carnival cruise ships -- including the running aground of the Costa Concordia in 2012 -- has contributed to a decline in cruise passengers. Carnival said that cumulative advance bookings for the rest of 2013 are behind those of last year, even with lower ticket pricing.