Latest penalty takes EU's Google fines tally to more than €8bn
Google has promised to further change its online ad system after being hit with a €1.5bn fine from the European Commission.
This week's fine brings to €8.3bn the amount Google has had to pay in fines.
The search giant was adjudged to have abused its dominant advertising position by locking out rivals on its own service and for third-party websites using its AdSense system.
"The commission has fined Google €1.49bn for illegal misuse of its dominant position in the market for the brokering of online search adverts," said EU competition commissioner Margrethe Vestager.
"Google has cemented its dominance in online search adverts and shielded itself from competitive pressure by imposing anti-competitive contractual restrictions on third-party websites.
"This is illegal under EU antitrust rules. The misconduct lasted over 10 years and denied other companies the possibility to compete on their merits and to innovate and to consumers the benefits of competition."
The fine has been calculated on the basis of the value of Google's revenue from online search advertising intermediation in the European Economic Area.
Google is also liable to face civil actions for damages that can be brought before the courts of EU member states "by any person or business affected by its anti-competitive behaviour", according to the commission.
The penalty is the latest in a series of fines accumulated by Google from the EU's administrative arm.
In 2017, the commission fined the tech giant €2.42bn for abusing its dominance as a search engine by giving an illegal advantage to Google's own comparison shopping service.
Last July, the commission fined Google €4.34bn for "illegal practices regarding Android mobile devices" to strengthen the dominance of Google's search engine.
The company's chief legal officer, Kent Walker, said that the firm accepted the fine and was ready to make changes to its system.
"We've already made a wide range of changes to our products to address the commission's concerns," he said.
"Over the next few months, we'll be making further updates to give more visibility to rivals in Europe."
The company's punishment comes as it announced a major online gaming platform called Stadia, intended to compete in the €120bn games industry.