London: Apple and five of the world's biggest publishers are under investigation for colluding to push up the price of electronic books by as much as 50 percent. The publishers involved include Rupert Murdoch's HarperCollins, and Penguin, which is owned by Britain's Pearson Group.

The European Commission is probing claims that Apple and the five publishing houses -- HarperCollins, Penguin, Hachette Livre, Simon & Schuster and Germany's Verlagsgruppe Georg von Holtzbrinck -- have worked together to keep eBook prices artificially high.

It is also suggested that the arrangement killed competition by ensuring that Apple's rivals, such as Amazon and Kobo, could not undercut its prices.

The boom in eBooks is a goldmine for publishers and technology firms, because the costs are a fraction of those involved in printing, transporting and selling books.

Despite the savings, the prices of blockbuster eBooks are often higher than the real thing.

For instance, Apple's iTunes store is offering an eBook download of the biography of its founder Steve Jobs for 12.99 pounds. Amazon charges just 11.97 pounds for the hardback version.

Stephen King's novel 11.22.63 is available for 9.99 pounds as an Apple eBook, compared with 8.20 pounds for the real book from Amazon.

The European Commission on Tuesday announced a probe to discover whether the publishers have 'engaged in anti-competitive practices'.

A parallel lawsuit has been launched against publishers and Apple in the US. It suggests eBook prices have been inflated by 33 to 50 percent as a result of collusion.

It has quoted a Pearson spokesman as saying: “Pearson does not believe it has breached any laws.”

Apple declined to comment.

Agencies