In an unprecedented decision, European Union antitrust regulators targeted Google‘s lucrative digital advertising business, ordering the tech giant to sell off some of its ad business to address competition concerns.

Following an investigation, the European Commission, the bloc’s executive branch, and top antitrust enforcer stated that “only mandatory divestment by Google of part of its services” would satisfy the concerns.

The EU’s 27 member states have led the global movement to crack down on Big Tech companies, but it has previously relied on issuing massive fines, including three antitrust penalties worth billions of euros (dollars) for Google.

It’s the first time the EU has ordered a tech titan to split up key business assets.

Google can now make its case before the commission issues its final decision. A request for comment was not immediately returned by the company.

The decision is the result of a formal investigation launched in June 2021 to determine whether Google violated EU competition rules by favoring its online display advertising technology services over rival publishers, advertisers, and advertising technology services.

The investigation into Google’s use of YouTube’s dominant position to favor its ad-buying services by imposing restrictions on rivals was one focus of the commission’s investigation.

Google’s ad tech business is also being investigated by the UK’s antitrust watchdog and is being sued in the US, Associated Press reported.

Previously, Brussels fined Google more than 8 billion euros (now USD 8.6 billion) in three separate antitrust cases involving its Android mobile operating system, shopping, and search advertising services.

All three penalties are being appealed by the company. Last year, an EU court reduced the Android penalty to 4.125 million euros. EU regulators have the authority to levy fines of up to 10 percent of a company’s annual revenue.