LONDON (AP) -- European Union regulators have launched a fresh antitrust investigation of Google, this time over whether the U.S. tech giant is stifling competition in digital advertising technology.
The European Commission said Tuesday that it has opened a formal investigation into whether Google violated the bloc's competition rules by favoring its own online display advertising technology services at the expense of rival publishers, advertisers and advertising technology services.
The commission, the EU's executive arm and the bloc's top antitrust enforcer, is looking in particular at whether Google is restricting access by third parties to user data for ad purposes on websites and apps.
"Thousands of European businesses use our advertising products to reach new customers and fund their websites every single day," Google said in a prepared statement. "They choose them because they're competitive and effective. We will continue to engage constructively with the European Commission to answer their questions and demonstrate the benefits of our products to European businesses and consumers."
The investigation signals a renewed effort by Margrethe Vestager, the EU commission's competition chief and executive vice president for digital, to rein in Google's market power. She has already slapped Google with a total of 8.2 billion euros (now $9.7 billion) worth of fines in three separate antitrust cases. There was criticism, however, that the fines were not much of a deterrent because the company could easily afford them.
"Online advertising services are at the heart of how Google and publishers monetize their online services," Vestager said. Google collects data to be used for targeted advertising while it also sells advertising space and acts as a middleman between online advertisers and publishers, she said.
"We are concerned that Google has made it harder for rival online advertising services to compete in the so-called ad tech stack," Vestager said.
The EU Commission said it was investigating the ways Google uses technology to broker display ad sales between online advertisers and publishers.
For example, it's looking at the restrictions Google puts on advertisers, publishers and competing ad brokers to access data about the identity and behavior of users that Google's own ad services have access to. Such data can be used to tailor online ads to individual web users.