Alphabet unit Google lost an appeal to a 2.42-billion-euro ($2.8-billion) European antitrust decision on Wednesday, a major win for the bloc’s competition chief Margrethe Vestager in the first of three court rulings that will strengthen the EU's push to regulate big tech.

Vestager sanctioned the world's most popular internet search engine in 2017 for favoring its own price-comparison shopping service to give it an unfair advantage against smaller European rivals.

The shopping case was the first of a trio of decisions that has seen Google rack up a total of 8.25 billion euros in EU antitrust fines in the last decade. The company could face yet more defeats in the other two cases involving its Android mobile operating system and AdSense advertising service, where the EU is seen to have stronger arguments.

The court ruling will strengthen Vestager's hand in her investigations into Amazon, Apple and Facebook.

"The General Court largely dismisses Google's action against the decision of the Commission finding that Google abused its dominant position by favoring its own comparison shopping service over competing comparison shopping services," the Court said.

"Google departed from competition on the merits," judges said.

The court said the Commission correctly found that Google's practices harmed competition and swatted away the company's argument that the presence of merchant platforms showed there was strong competition.

The court backed the EU fine, citing the serious nature of the infringement and the fact that "the conduct in question was adopted intentionally, not negligently."

Google said it would review the judgment and that it has already complied with the Commission's order to ensure a level playing field for rivals. It did not say if it would appeal to the EU Court of Justice (CJEU), Europe's top court.

The Commission welcomed the ruling, saying it would provide legal clarity for the market.

"The Commission will continue to use all tools at its disposal to address the role of big digital platforms on which businesses and users depend to, respectively, access end users and access digital services," the EU executive said in a statement.

Rivals such as U.S. search Yelp and those in the travel, restaurant and accommodation industries will be hoping that Vestager's victory will revive other dormant investigations triggered by their complaints.

The EU watchdog is currently focusing its energies on Google's use of data and its digital advertising business. The company is now seeking to settle the latter case, a person familiar with the matter has told Reuters.

Separately, on Tuesday, the UK Supreme Court blocked https://www.reuters.com/world/uk/uk-supreme-court-blocks-43-bln-google-class-action-over-iphone-tracking-2021-11-10 a planned $4.3 billion British class action against Google over allegations the internet giant unlawfully tracked the personal information of millions of iPhone users.

To augment her antitrust powers, Vestager last year proposed new landmark tech rules that will force U.S. tech giants to change their business models to ensure a level playing field for rivals.

The case is T-612/17 Google and Alphabet v Commission (Google Shopping).

($1 = 0.8648 euros)