LONDON, June 5 The European Commission's anti-trust officials are investigating a row between online retailer Amazon and French publisher Hachette.
Amazon has delayed the delivery of some Hachette Book Group titles and removed an option to pre-order "The Silkworm," by Harry Potter author J.K. Rowling writing as Robert Galbraith.
The companies themselves - Hachette, the fourth largest U.S. book publisher, is owned by France's Lagadere SCA - have not given details about the basis for the dispute but several media reports have indicated it is over the pricing of e-books.
"We are trying to understand what's going on there. We are looking into this and trying to understand," EU Competition Commissioner Joaquin Almunia told reporters on the sidelines of a conference in London.
Amazon has been accused before of using hardball tactics in fights with book publishers which have angered book lovers but antitrust experts have said that regulators like the European Commission are unlikely to intervene in what appear to be business disputes.
In December 2012, European Union regulators ended an antitrust probe into e-book prices, accepting an offer by Apple and four publishers to ease pricing restrictions on Amazon and other retailers.
The decision handed Amazon a victory in its attempt to sell e-books cheaper than rivals in a fast-growing market that publishers hope will boost revenue and customer numbers.
(Reporting by Huw Jones; Editing by Sophie Walker)