The European Commission, which has been investigating the case involving the unit of Alphabet since 2015, could issue its decision in the week of July 9, although the timing might change.

As a deterrent to others, the EU penalty is likely to top the record 2.4-billion-euro (2 billion pounds) fine handed out to Google last year for unfairly favouring its shopping service, sources told Reuters last year.

The EU competition enforcer will also tell Google to stop its anti-competitive practices such as licensing deals which prevent smartphone makers from promoting alternatives to apps such as Google Search and Maps.

Android is the most important of three EU cases against world No. 1 internet search engine Google because of its huge growth potential.

EU-mandated changes however may have little impact on Google because of its market power and the benefits of sticking with the company, industry executives, analysts and even its critics have said.

The Commission declined to comment. Google pointed to a 2016 blog by its general counsel Kent Walker who rejected the EU charges.

Google recently sought a closed-door hearing in a bid to present its case to senior Commission officials and national competition agencies after being told of new details and evidence which the regulator plans to use against the company, other people with direct knowledge of the matter said.

Its request was denied.

A third case where Google was accused of blocking rivals in its online AdSense search advertising in 2016 is likely to drag on to the end of the year or even later, other people said. The company has since stopped its alleged anti-competitive behaviour.

(Reporting by Foo Yun Chee; Editing by Edmund Blair)

By Foo Yun Chee