The Commission, which is in charge of antitrust issues in the European Union, accused Google in April of cheating competitors by distorting Internet search results in favor of its Google shopping service and at the same time opened the Android probe.

"On the formal investigation when it comes to Android, we still haven't finalised that. So it is still open whether it will go one way or the other," Vestager told a news conference.

"We looked into the case before we formally opened it and of course the reason why we put quite a lot of resources into it is because we have concerns if things are as they should be, if totally by the book."

(Reporting by Gilbert Reilhac, writing by Philip Blenkinsop)