Southwest Airlines and SeaWorld mutually agreed not to renew their 25-year-old marketing partnership, which expires at the end of the year.
The promotional ties began in 1988 and promoted Southwest as the official airline of SeaWorld. The airline also painted three aircraft in a black-and-white design resembling the coloration of a SeaWorld killer whale, Shamu.
The companies said in a statement that they decided not to renew the contract based on shifting priorities, but animal rights activists are taking some credit, citing a number of petition at Change.org protesting the use of captive whales for entertainment.
Some entertainers have opted out of performances at SeaWorld because of the controversy.
The companies said they will continue to work together through Southwest Vacations.