JK Rowling, who became the world's first billion dollar author on the back of Harry Potter's success, has given the go-ahead for the creation of a Florida theme park dedicated to the schoolboy wizard.

"The plans I have seen look incredibly exciting and I don't think fans of the books or films will be disappointed," Rowling said of the Orlando park that is scheduled to open in 2009.

The park is a joint venture between Warner Bros Entertainment, whose Potter films have so far grossed more than $3.5 billion worldwide, and Universal Orlando Resort.

In a statement rich in entertainment hyperbole, the builders of "The Wizarding World of Harry Potter" said they planned to "create the world's first immersive Harry Potter themed environment".

Barry Meyer, chairman and CEO of Warner Bros. Entertainment, said: "Over the years we've received thousands of letters from fans around the world wishing they could visit Hogwarts (School) and the wonderful locations described in each of J.K. Rowling's beloved stories."

The park's opening could help to quell the withdrawal symptoms of Potter fans around the globe who have bought 320 million copies of her wizard tales and turned every one of the films into a box office hit.

Pottermania is set to scale new heights in July with the last novel hitting the bookstands and the latest film being launched in a deluge of global publicity.

"Harry Potter and the Deathly Hallows," the final instalment in her hugely successful series, is being released on July 21.

Rowling is to mark publication with a moonlight reading for fans at London's Natural History Museum.

Sweepstakes are being conducted by her British publisher Bloomsbury Publishing Plc and American publisher Scholastic to pick the winning fans.

"Harry Potter and the order of the Phoenix," the fifth film in a blockbuster series based on the books, is being given its official world premiere in London on July 3.

Rowling, whose books are always released under tight security, has said two characters will die in the seventh and final book but she has refused to give any clues.

The author has appealed to people to keep the end a secret: "I want the readers who have, in many instances, grown up with Harry, to embark on the last adventure they will share with him without knowing where they are going."

U.S. authors John Irving and Stephen King were so worried about the fictional hero's fate that they urged Rowling to spare the bespectacled hero.