In a major escalation of its antitrust battle with tech giants, the U.S. Department of Justice (DOJ) has proposed breaking up Google’s advertising technology business, following a federal judge’s ruling that the company has illegally monopolized key parts of the online advertising market.
The DOJ wants Google, owned by Alphabet Inc., to sell off its AdX ad exchange and its DoubleClick for Publishers (DFP) ad server platform. These tools play a crucial role in how digital ads are bought, sold, and displayed on millions of websites. The department argues that such divestitures are necessary to restore fair competition in the industry, which it claims Google has distorted for years.
The court filing, made late Monday, comes after U.S. District Judge Leonie Brinkema found in April that Google had “willfully acquired and maintained monopoly power” in the ad-tech market. This is just the latest blow to the Silicon Valley titan, which was previously found to hold an illegal monopoly in online search last year.
Google, however, has pushed back strongly. The company said that while it supports behavioral changes—like making its real-time ad bidding features more accessible to competitors—it believes the DOJ’s call to break up parts of its business goes too far and has no legal basis.
“The DOJ’s additional proposals to force a divestiture of our ad tech tools go well beyond the court’s findings, have no basis in law, and would harm publishers and advertisers,” said Lee-Anne Mulholland, Google’s VP of Regulatory Affairs.
AdX is a digital marketplace where publishers can sell leftover ad space to advertisers in real time. The DFP platform allows publishers to manage their digital ad inventory. Together, these tools have helped Google maintain dominance in how digital ads are distributed across the web.
Critics argue that Google’s control over these systems allows it to favor its own services, reduce revenue for publishers, and limit choices for advertisers. The DOJ’s lawsuit aims to open up the ecosystem to more players and reduce Google’s overwhelming influence.
A trial date has been set for September, where both sides will present arguments over what specific remedies should be imposed.
This isn’t Google’s first encounter with antitrust regulators. Last year, the company offered to sell AdX in Europe in a bid to appease EU investigators—but the proposal was rejected by publishers who felt it didn’t go far enough.
As Google prepares for another courtroom battle, all eyes will be on how this case could reshape the future of digital advertising—and potentially set a precedent for how the U.S. handles Big Tech monopolies.
