Google has launched an appeal against a record €2.4bn (£2.2bn) fine imposed by the European Commission.
In June, the Silicon Valley giant was found to have given its own online shopping service an illegal advantage in internet search results across 13 countries within the European Economic Area – including the UK.
Google is now set for a legal showdown in Brussels that could take years to resolve, and add further strain on already tense relations between the company and the EU.
Its appeal has been filed with the General Court of the European Union in Luxembourg.
Google is still obliged to pay up despite the legal challenge, but it can put the money in a locked account until the court reaches a decision.
At the time of the ruling, the tech giant had said it “respectfully” disagreed with the findings and would consider an appeal.
The European Commission had found that Google’s shopping service had seen traffic jump 45-fold in the UK when it began to abuse its dominance.
Meanwhile, its rivals saw a downturn – and some saw visitor numbers plummet by 85%.
Google had been given 90 days to stop the favouritism or face a penalty of up to 5% of the average daily turnover of its parent company Alphabet.
At the time of the ruling, Europe’s antitrust chief Margrethe Vestager said Google’s strategy for attracting customers to its online shopping service was not just about being better than rivals.
“Instead, Google abused its market dominance as a search engine by promoting its own comparison shopping service in its search results, and demoting those of competitors,” she said.
“What Google has done is illegal under EU anti-trust rules.
“It denied other companies the chance to compete on the merits and to innovate.
“And most importantly, it denied European consumers a genuine choice of services and the full benefits of innovation.”
The fine handed to Google was a significant hike on the previous record penalty of €1.06bn (£937m) dished out by the commission to US microchip firm Intel in 2009.
The EU is also investigating whether Google tried to squeeze out its rivals in online search advertising and through its Android mobile operating system.