The European Commission (EC) launched a formal investigation into potential anti-competitive practices by Google, adding to growing regulatory pressure on the search giant.

Central to the probe is establishing if Google favours its own online display advertising technology by restricting third-party access to user data.

EC EVP and Competition Commissioner Margrethe Vestager (pictured) explained Google is “present at almost all levels of the supply chain for online display advertising”.

As the world’s largest search engine, Google collects data advertisers use to target potential customers. It also runs several platforms used to sell and place online ads, and sells advertising on its own websites.

The EC explained Google has access to data about user identity and/or behaviour which is unavailable to other online publishers and advertisers. In addition, the company requires competitors to use its technology to purchase and display ads, the EC said.

It placed the value of Europe’s online display advertising market at €20 billion in 2019.

Google recently said it will withhold certain information from third parties when Android users opt out of personalised advertising. The EC said it wants to understand how this will impact competition and how it can ensure “all market participants protect user privacy in the same manner”.

The EC investigation follows a capitulation by Google to the regulator earlier this month, with the company pledging to level the playing field for competitors by displaying a list of top search engines on the home screens of new Android devices.

Google is also under investigation by Germany’s Federal Cartel Office as part of broader scrutiny also involving Apple, Amazon and Facebook.