Merlin Entertainments, the firm behind tourist attractions including Legoland, Alton Towers and Madam Tussauds, is set for a £3b flotation on the London Stock Exchange, according to reports.
Sky News claimed that a formal process to appoint investment banks to handle the process would start in the near future.
The company is owned by private equity firms Blackstone and CVC Capital Partners
Merlin chief executive Nick Varney said in the company's annual results in March that he would prefer a London listing for the business.
Merlin declined to comment.