People for the Ethical Treatment of Animals, based in Norfolk, Va., said the donor, whose name was not given, wants to replace the animals at SeaWorld parks with animatronic or virtual reality displays, the Orlando (Fla.) Sentinel reported Wednesday.

"We are very interested in this offer because the intelligent, social animals imprisoned at SeaWorld are ... denied everything that is natural and important to them -- all in the name of 'entertainment,'" PETA wrote in an Aug. 14 letter to Carlos Brito, chief executive of InBev NV/SA, which is to take over SeaWorld under its $52 billion agreement to purchase the Anheuser-Busch empire.

"We don't know how high this donor will go, but he is serious. Whales, dolphins and other marine life are very important to him," PETA spokeswoman Lisa Wathne said.