The European Commission has opened a new probe into Google, this time focused on the company’s massive online advertising business, Bloomberg reports. European Union regulators have already fined Google billions for violating the Digital Markets Act, and being found guilty of anticompetitive behavior in online advertising could add to that total.

While the Commission has yet to announce a formal investigation, Bloomberg writes that it has started contacting Google’s customers and competitors for information about its dominance across multiple online advertising markets. Regulators are particularly concerned that Google could be “artificially increasing the clearing price” of ad auctions “to the detriment of advertisers.” If the company is found to be violating the EU’s competition rules, Google could be fined 10 percent of its global annual sales.

Google’s approach to advertising to minors was reportedly already under investigation by the EU as of December 2024, and besides fines, regulators have ordered the company to open up Android to competing AI assistants and share search data with rivals. In the US, there’s also precedent for finding Google’s approach to online advertising anticompetitive.

A US federal judge found that Google is a monopolist in online advertising in April 2025, the conclusion of a legal battle that started with a Department of Justice lawsuit accusing the company of dominating the ad market and using its control to charge more and keep a larger portion of ad sales. The DOJ ultimately wants Google to sell its ad tech business, but a final decision hasn’t been reached as to how the company’s anticompetitive behavior should be remedied.