The Miami Seaquarium is being sold to a California-based company that is a subsidiary of Spanish theme park operator Parques Reunidos.
Palace Entertainment signed an agreement in the past month to buy the 38-acre park on Virginia Key.
Owner Wometco Enterprises will close the deal after the Miami-Dade County Commission votes on a resolution approving the purchase in the next few months.
The Seaquarium leases the land from the county and pays on a fluctuating scale based partly on revenues.
President and general manager Andrew Hertz said talks had been underway for more than two years. He did not disclose terms of the deal but said Palace Entertainment initiated the sale.
"We've never put ourselves up for sale," Hertz said. "Miami Seaquarium has never put the 'for sale' sign out there, but in my 18 years here, every year, we get two to three unsolicited offers."
Hertz said because the Seaquarium has been operating since 1955, there are "some areas of the park that obviously need a little bit of touch-ups and need a little bit of renovation."
The South Florida tourist attraction attracts half a million visitors annually. Perhaps the most popular attraction is Lolita the killer whale. Hertz promises Lolita will not be going anywhere.
"Nothing is going to change about how we operate and what we're doing," he said.