Daniel Radcliffe as Harry Potter in a scene from "Harry Potter and the Half-Blood Prince". [Agencies]

LONDON- Boy wizard Harry Potter is back in cinemas later this month with the sixth installment of the movie franchise, and another box office bonanza looks assured for the Warner Bros. studio.

"Harry Potter and the Half-Blood Prince" hits screens on July 15, promising high-speed action, dark and dangerous battles with the forces of evil, budding romance at Hogwarts school for wizards and the expected death of a prominent character.

The wait has been a long one for Potter fans around the world who have followed the fate of Harry and his friends through the seven best-selling books by British author J.K. Rowling.

Warner Bros. pushed the release date of Half-Blood Prince back from 2008, leaving a two-year gap since the fifth movie "Harry Potter and the Order of the Phoenix" and the final novel "Harry Potter and the Deathly Hallows".

The release of Potter books and films are major events for the entertainment industry, both because of the passion fans share for the stories, dubbed "Pottermania" in the media, and the amount of money they generate.

The seven Harry Potter books, which began in 1997, have sold more than 400 million copies worldwide and turned Rowling into a multi-millionaire publishing phenomenon.

MAGIC NUMBERS

The five movies released so far have grossed $4.5 billion in ticket sales, and box office experts see little reason to doubt that the sixth installment will fall within the $800 million to $1 billion range, a huge amount for a single film.

"This is just a remarkable franchise that has consistently drawn blockbuster numbers each time out, and it is hard to imagine this picture not continuing that trend," said Brandon Gray, president of tracking firm Box Office Mojo.

Pent-up demand is expected to ensure a big opening in the key North American market and in countries like Britain, after which word-of-mouth will be a key factor.

The fact that the Potter story is now complete may mean some fans lose interest, but U.S. advance online ticket sales look strong, according to MovieTickets.com.

Two films are being made from the Deathly Hallows book, part one scheduled for release in November 2010 and part two in July 2011.

In Half-Blood Prince, Hogwarts headmaster Dumbledore is intent on preparing student Potter for a final showdown with the evil Lord Voldemort, who is seeking to tighten his grip on the worlds of wizards and non-wizards, or "Muggles".

Love is in the air as Harry, played by Daniel Radcliffe, is drawn to Ginny, Ron (Rupert Grint) catches the eye of Lavender Brown and Hermione (Emma Watson) simmers with jealousy.

"It's all about sex, drugs and rock n' roll," British director David Yates told The Daily Telegraph. "Okay, maybe we should take the 'drugs' out. Really, this film is more sex, potions and rock n' roll."

Yates made Order of the Phoenix and is directing the Deathly Hallows pictures. Warner Bros. is a unit of Time Warner Inc.