European regulators on Wednesday announced formal antitrust charges against Google, accusing the tech giant of using its popular Android mobile operating system to push its own services over those of its rivals.

Google created strong incentives for device manufacturers, ensuring that the company’s search engine and browser would be dominant on Android devices, the European Commission alleged in a statement. “Based on our investigation thus far, we believe that Google’s behaviour denies consumers a wider choice of mobile apps and services and stands in the way of innovation by other players, in breach of EU antitrust rules,” the EU’s competition commissioner, Margrethe Vestager, said.

Google senior vice president and general counsel Kent Walker said the Android “business model keeps manufacturers’ costs low and their flexibility high, while giving consumers unprecedented control of their mobile devices.”

Google’s partner agreements are “entirely voluntary” and “anyone can use Android without Google,” he wrote.

Android maintains a far greater global share of the mobile operating market than Apple’s iOS. One reason is that Google offers the basic open-source operating system for free, which makes it the software of choice for many lower-cost phones from a slew of manufacturers. Google’s mobile operating system has a market share of more than 90 percent in the European Union.

The company then profits from mobile in other ways, such as advertising built into its products, including Search, as well as taking a cut of sales made through its Google Play app store.

According to the commission, Google obliges smartphone makers who want to pre-install Google’s popular app store to also pre-install Search and set it as the default search engine on those devices. And manufacturers who want Play Store or Search also have to pre-install Google’s Chrome browser.