Harry Potter and the Half-Blood Prince will hit the shops on July 16 next year, it has been announced.

Rowling wrote on her website: "I know you all expected this to happen on Christmas Day, but I was sure that those of you who celebrate Christmas have better things to do on the day itself than fight your way into my study, whereas those of you who don''t celebrate Christmas would definitely prefer not to wait until the 25th".

Despite being pregnant with her third child, Rowling said in her message that she''d been given the “time needed to tinker with the manuscript to my satisfaction and I am as happy as I have ever been with the end result.

"I only hope you feel it was worth the wait when you finally read it," she added.

With the new Potter book almost certain to come out in 2005, fans should be spared the seemingly interminable three-year wait between Potter IV, Harry Potter and the Goblet of Fire, and Potter V, Harry Potter and the Order of the Phoenix, which came out in the summer of 2003.

Today?s announcement will also be great news for booksellers. More than 100 million copies of the fantasy series, which debuted in 1997, are in print, and Order of the Phoenix sold an astonishing 5 million copies within 24 hours of publication.

Rowling has said that one of her characters will not survive her sixth book, but she refused to identify that character.

Potter himself is safe, at least for now. Rowling has said her teenage hero will survive until the seventh and final book in the series, but has refused to say whether he will reach adulthood.