The European Union's antitrust chief has formally accused Google of abusing its control in internet searches to the disadvantage of competitors, marking the start of official proceedings into whether the US internet giant forces its Android smartphone users to favour the company's own services and applications.

Margrethe Vestager, the EU Competition Commissioner, announced on Wednesday that she is "concerned that the company has given an unfair advantage to its own comparison shopping service".

According to the technology research company Gartner, Google's Android software, which is used by large mobile phone makers like Samsung, is the world's largest operating system with roughly an 81 percent market share. Apple holds a 15 percent stake, while Microsoft has a less than 3 percent share.

Europe has been investigating Google's alleged self-promotion for over five years and sought a settlement with Google, but has not filed in an official complaint until now, saying that the company has not fully addressed its concerns.

The formal accusation could mean years of legal arguing - as well as fines worth billions. The EU has the power to impose fines of 10 percent on annual revenue, adding up to some $6bn, and force the California- based company to overhaul its system for recommending websites in Europe.

Thomas Vinje, legal counsel for FairSearch Europe, a group that has been urging EU regulators to rein in Google, said that Wednesday's move was "a significant step towards ending Google's anti-competitive practices, which have harmed innovation and consumer choice".

Amit Singhal, the senior vice president of Google Search, said in a reaction that "while Google may be the most used search engine, people can now find and access information in numerous different ways, and allegations of harm, for consumers and competitors, have proved to be wide of the mark".

Google has 10 weeks to respond to all the allegations.

Source: Agencies