Judge Lets Google Keep AdX Despite Ad Tech Monopoly Ruling

A federal judge refused the DOJ's demand to break up Google's AdX exchange, opting for behavioral fixes while keeping the monopoly finding in place.

A federal judge has refused to order Google to sell its AdX advertising exchange, turning down the U.S. Justice Department's central demand in a closely watched ad tech antitrust case. U.S. District Judge Leonie Brinkema ruled that the company may retain the business even after the court concluded it had broken the law.

The outcome, delivered by the U.S. District Court, spares Google a forced breakup of its publisher advertising operation. Rather than compel a sale, Brinkema opted for conduct-based fixes, adopting most of the behavioral remedies that Google and the Justice Department had each put forward.

AdX is the auction marketplace through which online publishers offer their advertising space, matching that inventory with buyers in real time. The Justice Department had pushed for the exchange to be spun off entirely, arguing that a divestiture was needed to restore competition. Brinkema rejected that path.

The ruling does not disturb the court's underlying finding of wrongdoing. In April 2025, Brinkema determined that Google had unlawfully monopolized two segments of the market: tools that publishers use to serve ads, and the exchanges where that inventory is bought and sold. That conclusion remains fully in force.

In the earlier decision, the judge found that Google's practices caused real damage. She held that the company tied publishers to its own suite of advertising products, and that this lock-in hurt those publishers, undermined fair competition, and ultimately worked against consumers.

Why the judge chose conduct over a sale

Google had fought hard against divestiture. The company told the court that unwinding AdX would be an intricate technical undertaking, one that would require a drawn-out handover and, in its view, leave customers worse off. It framed a forced sale as disruptive rather than corrective.

The company also drew a distinction between what the Justice Department was asking for and a step it had previously been willing to take abroad. During an antitrust inquiry by the European Union, Google had floated selling AdX. It argued that the U.S. proposal was not the same as that earlier offer.

Brinkema's decision splits the difference between liability and punishment. Google carries the legal weight of having violated antitrust law, but escapes the structural penalty the government sought. Instead of dismantling part of the business, the court is betting that changes to how Google behaves can address the harm.

Google responds

Google marked the ruling with a statement posted on X and attributed to Lee-Anne Mulholland, who serves as Alphabet's vice president of regulatory affairs. The company's response accompanied a decision that leaves its publisher ad tech unit intact.

The practical effect is that Google's advertising exchange stays under its ownership and continues operating. The behavioral remedies now take the place of the sale the Justice Department wanted, and they will govern how the company conducts itself in the markets where it was found to hold monopoly power.

For the Justice Department, the result is partial. It secured and preserved a finding that one of the world's largest technology companies illegally monopolized key parts of the digital advertising supply chain. But it did not obtain the remedy it argued was necessary to loosen Google's grip on that market - a court-ordered breakup.

The ruling closes the remedies phase of a case that has tested how far courts will go in reshaping dominant technology firms. Here, the answer was that the monopoly finding stands, the exchange stays, and the fix comes through rules on behavior rather than a change in ownership.

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