London, Sept 19 : Brisingr, a new fantasy children's book, will be 'met with near Harry Potter-style demand' when it goes on sale on Sept 20, according to Waterstone's.
The third book in Christopher Paolini's Inheritance Cycle comes after more than 15 million copies have been sold of the first two books worldwide.
Toby Bourne, Waterstone's fiction and children's category manager, said Paolini's books had such wide-ranging appeal that Brisingr had the potential to become the Christmas best seller.
"There are some fantastic novels out this Christmas for both children and adults, but Brisingr has the potential to outsell all of them," the Telegraph quoted him, as saying.
"'Like Rowling and Philip Pullman, Paolini's books are great adventure stories but with a lot more going on in their pages than just non-stop action, and keep readers of all ages gripped," he added.
Claudia Mody, who buys children's books for the bookseller, also thinks that Paolini's series could follow a similar trajectory to JK Rowling's.
"It's our biggest pre-order campaign for anything since the final Harry Potter novel. Bigger than Sebastian Faulk's James Bond novel, Stephanie Meyer's Twilight or Delia Smith's How to Cheat at Cooking. It's going to be huge," she said.
"It wasn't until Harry Potter and the Prisoner of Azkaban that people started counting down the days before the new JK Rowling book was out. It's the same with Paolini - Brisingr is our most asked for book," she added.
Paolini is an American author who published his first book in the series, Eragon, when he was only 19.
It was picked up by Hollywood and turned into a film that earned 137 million pounds.