The Daily Telegraph said that, starting this fall, book covers will state whether they are intended for readers ages 5+, 7+, 9+, 11+ or 13+/teen.

"I don't mind anybody having an opinion about my books," Pullman, the author of the "His Dark Materials" fantasy trilogy, told the newspaper. "I don't mind a bookseller deciding they are for this age group or that, or a teacher giving one of my books to a child because they think it is appropriate. But I don't want to see the book itself declaring officially, as if with my approval, that it is for readers of 11 and upwards or whatever. I write books for whoever is interested. When I write a book I don't have an age group in mind. ... The book should be suited to the individual child."

Introduced by some of England's top publishers, the guidelines have met with protest from a group of more than 80 authors, illustrators, librarians, teachers and booksellers, the Telegraph said.

An online petition at www.notoagebanding.org criticized the idea of rating books as "ill-conceived" and "damaging to the interests of young readers."