The European competition watchdog has fined Google 2.42 billion euros (£ 2.1billion) for abusing its dominance as a search engine.
The European Commission said the tech giant had abused its market dominance as a search engine by handing an "illegal advantage" to its comparison shopping operation.
In a statement, commissioner Margrethe Vestager said: "Google has come up with many innovative products and services that have made a difference to our lives.
"That's a good thing. But Google's strategy for its comparison shopping service wasn't just about attracting customers by making its product better than those of its 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."