Google earns 90% of its revenue from adverts shown to consumers in response to a search engine query, the EC ruling said.
But in 2004 it entered the separate market of comparison shopping in Europe – a service first called Froogle, later known as Google Product Search, then Google Shopping.
It allows consumers to compare products and prices online and find deals from all types of retailers.
When Google entered this market there were already a number of established players and its initial market performance was “relatively poor”, the EC said, and from 2008 it began to implement a “fundamental change in strategy”.
The ruling found that search results gave prominence to Google’s own shopping service and demoted rivals, giving it a “significant advantage”.
Google’s comparison service was then found to have made significant gains in traffic at the expense of its rivals, with a 45-fold increase in the UK, 35-fold in Germany and 19-fold in France.
Rival websites saw declines of 85% in the UK, up to 92% in Germany and 80% in France – sudden drops which the commission said could not be explained by other factors.
Google has now been told it must “apply the same processes and methods to position and display rival comparison shopping services in Google’s search result pages as it gives to its own comparison shopping service”.
The EC has already come to preliminary conclusions in two separate cases – involving the Android operating system and the AdSense advertising platform – that Google has abused a dominant position.
Google senior vice president Kent Walker said: “When you use Google to search for products, we try to give you what you’re looking for.
“Our ability to do that well isn’t favouring ourselves, or any particular site or seller – it’s the result of hard work and constant innovation, based on user feedback.
“Given the evidence, we respectfully disagree with the conclusions announced today.
“We will review the Commission’s decision in detail as we consider an appeal, and we look forward to continuing to make our case.”
Google said the EC should have considered another reason why rival shopping services may not have done so well – because major retail platforms such as Amazon had instead become the first port of call for product searches.
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behaviour or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional
Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes.The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.