The European Union Competition Committee has opened a formal antitrust investigation into agency pricing agreements on e-books made between Apple and Penguin, Hachette, HarperCollins, Simon & Schuster and the Holtzbrinck Group (Macmillan). The European Commission said it began the probe to examine “whether these publishing groups and Apple have engaged in illegal agreements or practices that would have the object or effect of restriction competition” in Europe.

With the announcement by the EU, Britain’s Office of Fair Trading said it was dropping its look into possible antitrust violations to let the larger organization take the lead in the matter. Representatives from Harper, Pearson and S&S said they will cooperate with the investigation with Pearson noting that it “does not believe it has breached any laws.” A spokesperson for Hachette Livre had no comment.

The investigation follows remarks made by EU Competition Commissioner Joaquin Almunia last month about fighting “artificial restrictions imposed by some companies to cross-border trade” which are “particularly important in the digital area where I have already started to look at the distribution practices of certain products such as e -books.”