At the high end, the IPO would raise $540 million.
SeaWorld and selling shareholders are selling 10 million shares each.
The company plans to use the funds it raises to repay debt.
SeaWorld, which is perhaps best known for its performing killer whale Shamu, applied for a $100 million IPO in December and raised this to $500 million on Monday.
The amount of money a company says it plans to raise in its IPO filings is used to calculate registration fees. The final size of the IPO could be different.
SeaWorld owns 11 theme parks under brands such as SeaWorld, Busch Gardens and Sesame Place, caring for more than 67,000 animals.
Established operators in the U.S. theme park industry, which hosts about 315 million visitors per year, have proved resilient in a weak economy.
Shares of amusement park operator Six Flags Entertainment Corp have risen about 19 percent since the beginning of the year, while those of Cedar Fair LP have risen about 16 percent.
Blackstone acquired SeaWorld from brewer Anheuser-Busch InBev SA in December 2009 for $2.3 billion, according to the private equity firm’s website.
U.S. IPO volumes rose about 65 percent in the first quarter as private equity-backed companies rushed to take advantage of a surge in share prices.
Goldman Sachs and JPMorgan Securities are the lead underwriters for the offering. ()
Orlando, Florida-based SeaWorld intends to list on the New York Stock Exchange under the symbol “SEAS”.