Potter rival Brisingr fastest selling children's book

Brisingr, by American author Christopher Paolini, sold more than 45,000 copies on its first day, according to its publisher Random House. It is the third book in Paolini's Inheritance Cycle series, about a dragon rider, Eragon, and his steed, Saphira.

Before it went on sale Waterstone's, the bookseller, predicted it would be met with "near Harry Potter-style demand." The first of the series, Eragon, published when Paolini was just 19, was made into a successful Hollywood film.

Although the 45,000 first day sales figure is likely to send it to the top of the children's bestseller charts, it is still dwarfed by those for JK Rowling's books.

Harry Potter and the Deathly Hallows, the seventh instalment in the series, sold more than 2.6 million copies on its first day in Britain when it went on sale in July 2007.