Three of the largest US book publishers are to hike the prices of their electronic books after the introduction of Apple's iPad tablet computer forced Amazon to abandon its one-price-fits-all policy, Information Week reported Monday.

Amazon was able to dictate the 9.99-dollar price because its Kindle electronic reader dominated the market for electronic books. But the introduction last month of the iPad gave publishers a new outlet and MacMillan said it would withdraw its books from Amazon unless it was given the same pricing flexibility it had with Apple, when it can set prices at between $12.99 and 14.99 per book.

Amazon initially resisted the move but caved in to MacMillan's boycott threats last week.

According to the report, HarperCollins and Hachette Book Group are now demanding the same flexibility. In the long run, this will enable Hachette to continue to invest in and nurture authors' careers - 'from major blockbusters to new voices', said Hachette chief executive David Young in an email quoted in the article.

'Without this investment in our authors, the diversity of books available to consumers will contract, as will the diversity of retailers, and our literary culture will suffer.'