Los Angeles, Aug 16: Harry Potter fans clamouring for the next movie instalment of the boy wizard's adventures will have to wait until 2009 after a decision to postpone release of the new film.

A statement from Warner Brothers said the original November release date for Harry Potter and the Half-Blood Prince, the sixth film adaptation of J K Rowling's books, had now been shifted to July 17, 2009.

Warner president Alan Horn said the decision was taken to guarantee the studio a major summer blockbuster in 2009, and was partially explained by the Hollywood writers' strike, which paralysed the industry this year.

"Like every other studio, we are still feeling the repercussions of the writers' strike, which impacted the readiness of scripts for other films - changing the competitive landscape for 2009 and offering new windows of opportunity that we wanted to take advantage of," Horn said.

"We agreed the best strategy was to move Half-Blood Prince to July, where it perfectly fills the gap for a major tent pole release for mid-summer."

A "tent pole" film is usually a big-budget, heavily promoted film relied on by a studio to turn a profit rapidly. Horn said a summer release date would benefit box office revenues, citing the most recent Harry Potter film, the second-highest grossing film in the franchise.