The European Commission has this morning announced that it is opening formal proceedings to investigate the sale of ebooks across the EU. Together with the British Office of Fair Trading, the Commission has already been taking an interest in the way digital books have been priced by publishers, and now that's been escalated to a fully fledged antitrust probe. Five publishers are named in the announcement, including HarperCollins, Penguin, and Simon & Schuster, though there's also a surprising namedrop for Apple. The issue at hand is whether those content providers engaged in anti-competitive practices — in this case most likely referring to collusion in setting prices at a certain level instead of competing — which the Commission says could have happened "with the help of Apple."

The iBooks digital store and the deals agreed to sell books through it are the likely subjects of the EC's scrutiny, with the Commission saying it'll examine "the character and terms of the agency agreements entered into by the above named five publishers and retailers for the sale of e-books." This is only the first step in the investigation process and the EC notes that it's not going to prejudge the outcome.