The European Union has charged Google with abusing its dominance in Internet searches and opened a probe into its Android mobile system, massively raising the stakes in its five-year antitrust battle with the tech giant. Wednesday’s move could lead to billions in fines for Google if the case shows that the way it does business in the 28-country bloc is illegal, as well as years of legal wrangling. The EU can impose fines of 10 percent of annual revenue, or some $6 billion, and force the company to overhaul its system for recommending websites in Europe. The EU executive commission said it found that Google “gives systematic favorable treatment’’ to its Google Shopping at the expense of others in its general search results. Margrethe Vestager, the EU’s competition commissioner, said that was a problem because Google is so dominant in Europe. It has a market share of over 90 percent of Internet searches in the EU, compared with around 70 percent in the US. “It is not based on the merits of Google Shopping that Google Shopping always comes up first,’’ she said. “Dominant companies have a responsibility not to abuse their powerful market position.” Though Wednesday’s charges centered on the shopping service, the EU said it was pursuing other issues against Google, including a probe of its online ad business. Vestager said her chief goal is to make sure multinationals do not artificially deny European consumers as wide a choice as possible or stifle innovation. She noted that one in four companies complaining about Google were US rivals. Monique Goyens, director general of the European Consumer Organisation, said that “Google’s market share means it essentially decides which companies are placed in the shop window”. In the separate probe into Android, the EU alleges that Google is breaking the rules by obstructing rival operating systems, applications and services, hurting both consumers and innovators. Google has 10 weeks to respond to all the latest allegations. Amit Singhal, the senior vice president for Google Search, said 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.’’