The phone call is in line with EU regulatory procedures whereby companies are informed of an imminent antitrust decision.

The European Commission and Google declined to comment.

Vestager is set to levy a record-breaking fine and order Google to halt its anti-competitive business practices on Wednesday, sources have told Reuters.

Her ruling comes just over a year after she slapped a landmark 2.4-billion-euro (£2.1 billion) penalty on Google, a unit of Alphabet Inc, for promoting its shopping service over those of competitors.

The Android penalty is likely to exceed the 2017 fine because of the broader scope of the Android case, sources familiar with the matter have told Reuters.

(Reporting by Foo Yun Chee; editing by Philip Blenkinsop)

By Foo Yun Chee