Google has been fined €2.95bn (£2.5bn) by the EU for allegedly abusing its power in the ad tech sector – the technology which determines which adverts should be placed online and where.

The European Commission said on Friday the tech giant had breached competition laws by favouring its own products for displaying online ads, to the detriment of rivals.

It comes amid increased scrutiny by regulators worldwide over the tech giant’s empire in online search and advertising.

Google told the BBC the Commission’s decision was “wrong” and it would appeal.

“It imposes an unjustified fine and requires changes that will hurt thousands of European businesses by making it harder for them to make money,” said Lee-Anne Mulholland, global head of regulatory affairs at Google.

“There’s nothing anti-competitive in providing services for ad buyers and sellers, and there are more alternatives to our services than ever before.”

US President Donald Trump also attacked the decision, saying in a post on social media it was “very unfair” and threatening to launch an investigation over European tech practices that could lead to tariffs.

“As I have said before, my Administration will NOT allow these discriminatory actions to stand,” he wrote.

“The European Union must stop this practice against American Companies, IMMEDIATELY!”

Trump has repeatedly criticised the bloc’s fines and enforcement actions against US tech firms in recent months, though the US government has brought its own lawsuits over Google’s monopoly of the online ad market.

Earlier this week, the Commission denied reports it had delayed the announcement of Google’s fine amid tensions over trade relations between the EU and the US.

In the Commission’s decision on Friday, the Commission accused Google of “self-preferencing” its own technology above others.

As part of its findings, it said Google had intentionally boosted its own advertising exchange, AdX, over competing exchanges where ads are bought and sold in real-time.

Competitors and publishers faced higher costs and reduced revenues as a result, it said, claiming these may have been passed to consumers in the form of more expensive services.

The regulator has ordered the company to bring such practices to an end, as well as pay the nearly €3bn penalty.

The Commission’s fine is one of the largest fines it has handed down to tech companies accused of breaching its competition rules to date.

In 2018 it fined Google €4.34bn (£3.9bn) – accusing the company of using its Android operating system to cement itself as the dominant player in that market.

Teresa Ribera, executive vice president of the Commission, said in a statement on Friday the regulator had factored in previous findings of Google’s anti-competitive conduct when deciding to levy a higher fine.

“In line with our usual practice, we increased Google’s fine since this is the third time Google breaks the rules of the game,” she said.

Ms Ribera also warned the tech giant it had 60 days to detail how it would change its practices, or else the Commission would look to impose its own solution.

“At this stage, it appears the only way for Google to end its conflict of interest effectively is with a structural remedy, such as selling some part of its ad tech business,” she said.