EU is preparing AdWords antitrust complaint against Google

Google may soon be the target of a third set of charges from Europe's top antitrust authority, this time concerning the advertising services that generate the majority of its revenue.

The European Commission has asked companies that submitted evidence to its antitrust investigation to remove confidential material from their documents, a step that often precedes the filing of formal charges, Politico.eu and Bloomberg reported Monday.

The Commission has already filed two previous sets of antitrust charges against Google. The most recent, concerning the company's tying of its online services and apps to use of the Android operating system, were filed two months ago, following a relatively brief investigation begun in April 2015.

The first charges, filed the day the Android antitrust investigation began, concerned the company's comparison shopping service, and grew out of an investigation begun in November 2010.

As part of that same initial investigation, the Commission said it would examine whether Google imposed exclusivity obligations on its advertising and distribution partners, or prevented advertisers from moving their campaign data over to competing online advertising platforms, but as time went on it seemed to be losing interest in pressing charges related to the advertising business.

That part of the investigation was reopened earlier this year, and European Commissioner for Competition Margrethe Vestager told Bloomberg in May that she hoped it could be concluded in a reasonable timeframe.

If found guilty of abusing a dominant market position, Google could face a fine for each of the charges of up to 10 percent of its worldwide revenue, which last year totaled US$74.5 billion.

Google's advertising business has attracted the attention of antitrust authorities around the world. The Canadian Commissioner of Competition began an investigation in 2013, while the Competition Commission of India opened its own investigation in May 2014.