'Harry Potter and the Half-Blood Prince' has sold an amazing 6.9 million copies in the first 24 hours of it being released. Not only has that broken the record held by the previous book in the series, 'Harry Potter and the Order of the Phoenix', that figure is more than many novels sell in a lifetime.

The latest in the Harry Potter chronicles has averaged better than 250,000 sales per hour.  Lisa Holton, President of Scholastic Children's Books (Rowling's U.S. publisher) said, "This is a cause for celebration, not just for Scholastic, but for book lovers everywhere."

Book 5 of the Harry Potter series sold 5 million copies in the first 24 hours, when it was released in 2003. As some stores ran out of books then, Scholastic has already increased the print run for book 6. 

However, these figures are only for the United States. Sales figures for Britain are expected to be available on Monday.