Google has been fined €2.4bn ($2.7bn; £2.1bn) by the European Commission after it ruled the company had abused its power by promoting its own shopping comparison service at the top of search results.
The amount is the regulator’s largest penalty to date against a company accused of distorting the market.
The ruling also orders Google to end its anti-competitive practices within 90 days or face a further penalty.
The US company may decide to appeal.
However, the decision could set a precedent that determines how the EU’s civil service handles related complaints about the prominence Google gives to its own maps, flight price results and local business listings within its search tools.