Feeds
The sixth movie in the wizard series was initially scheduled to hit cinemas on November 21, but was last week pushed back to a July 2009 release.
Horn said in a statement: "Many of you have written to me to express your disappointment in our moving Harry Potter And The Half-Blood Prince to Summer 2009.
"Please be assured that we share your love for Harry Potter and would certainly never do anything to hurt any of the films. Over the past ten years, we have nurtured and protected each film, and the integrity of the books upon which they are based, to the best of our ability.
"The decision to move Harry Potter And The Half-Blood Prince was not taken lightly, and was never intended to upset our Harry Potter fans. We know you have built this series into what it is, and we thank you for your ongoing enthusiasm and support."
Horn reminded fans that the delay means that the release gap between Half-Blood Prince and the first part of Harry Potter And The Deathly Hallows, to arrive in cinemas in November 2010, will be less than 18 months.
He concluded: "I am sorry to have disappointed you now, but if you hold on a little longer, I believe it will be worth the wait."
