Despite having already slapped Google with a hefty fine of more than $40 billion, the European Union regulators are poised to hit the tech giant once again.

On Monday, June 12, Eastern Time, media reports, citing sources familiar with the matter, announced that the European Commission will soon disclose another antitrust charge against Google. This charge targets the heart of Google's ad tech business model, with the penalty's amount to be revealed as early as Wednesday of the same week.

Observers regard this as the most significant charge during the current five-year tenure of the European Commission, marking an escalation in the EU's antitrust regulation against Google.

Financial statements reveal that advertising is the most crucial revenue source for Google's parent company, Alphabet. In the first quarter of this year, Google's ad revenue slightly decreased by 0.2% year-on-year to $54.55 billion. However, this decline was significantly less than the anticipated 1.6% drop by analysts, representing approximately 78% of Alphabet's total revenue.

It's noteworthy that over the past six years, the European Commission has already imposed three substantial fines on Google, each exceeding one billion dollars. In total, the fines slightly surpass 8 billion euros, equivalent to about $8.6 billion.

In June 2017, the European Commission fined Google 2.42 billion euros because the tech giant was found to have illegally downgraded competitors' rankings in shopping search results. Google appealed the decision, but the General Court of Europe dismissed the appeal in November 2021.

In 2019, the Commission fined Google 1.49 billion euros for squeezing out competitors in internet advertising services, a case still under appeal.

In 2018, the Commission penalized Google 4.34 billion euros, approximately slightly over $5 billion, for monopolizing the Android system. This marked the highest single fine ever imposed by this regulatory body.

In September of last year, Google lost an appeal over this antitrust case regarding the Android system. The General Court of Europe upheld the European Commission's decision, albeit reducing the fine to 4.1 billion euros. Google still disputed the ruling, taking the appeal to the highest court.

The EU's allegations that Google's digital advertising business violates antitrust laws come as no surprise.

The EU began a related antitrust investigation in June 2021, looking into how Google might have blocked competitors from accessing user data for online advertising and potentially prevented competitors from using their own data. In September last year, after Portugal's competition regulatory authority submitted new evidence, the European Commission expanded the scope of its investigation.

Moreover, the UK's competition regulatory body is also investigating Google's ad technology, with related litigation taking place in the United States.