This follows a federal court’s recent decision, where Google was found guilty of deliberately using its market power to shut out competition in online advertising. Now, the DOJ wants more than accountability, it wants structural change.

According to the newly filed document, the DOJ is not just pushing for asset sales. It wants Google out of the ad exchange business entirely for a decade after the AdX sale. 

That’s an aggressive timeline, stressing how seriously U.S. regulators are taking this case. The department argues that AdX and DFP weren’t just Google ads products, but were the backbone of a system Google used to take over the market and restrict rivals.

In the DOJ’s own words: “This comprehensive set of remedies—including divestiture of Google’s unlawfully obtained monopolies and the products that were the principal instruments of Google’s illegal scheme—is necessary to terminate Google’s monopolies, deny Google the fruits of its violations, reintroduce competition into the ad exchange and publisher ad server markets, and guard against reoccurrence in the future.”

The plan doesn’t end with asset sales. The DOJ wants to dismantle Google’s hold on the infrastructure of online ads by forcing its ad buying tools—like AdWords—to interact fairly with all third-party systems. 

That includes making them interoperable “on non-discriminatory terms with respect to bidding, matching, placement of ads, or provision of information, except at the express instruction of an advertiser.”

Behind this case is an accusation that Google made sure publishers lost money if they didn’t use AdX. That’s not a business strategy—it’s market strangulation. By tightly integrating the ads products, AdX with DFP, the DOJ says Google locked in websites and starved out alternatives.

Google has not taken this lightly. In its response, the company’s Vice President of Regulatory Affairs, Lee-Anne Mulholland, rejected the DOJ’s expanded demands.

“The DOJ conceded Google’s proposed ad tech remedy fully addresses the Court’s decision on liability. 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,” she stated.

Google is instead offering a softer set of solutions: making real-time AdX bids accessible to third-party ad servers and submitting to oversight from an independent compliance monitor—for three years. But to the DOJ, these gestures fall short.

This antitrust fight is only one front. In another case, U.S. regulators are pressing Google to sell off its Chrome browser, following a court ruling that confirmed the company’s monopoly in online search.

The U.S. government is not simply interested in fines or restrictions, it wants to break Google’s monopoly by pulling the system apart, piece by piece. 

Whether that happens will depend on the court’s final ruling on the proposed remedies. 

On Friday, Google will ask U.S. District Judge Leonie Brinkema to reject the idea of dismantling its advertising tools, which are central to the digital ad ecosystem.

The case focuses on the competition within the market for ad tech services used by website publishers to sell online ads. At the hearing in Alexandria, Virginia, Judge Brinkema will consider the possible remedies to restore fair competition in the sector, with more detailed discussions to follow on specific actions.

Google is working hard to avoid the drastic move of selling off its advertising assets, hoping to head off a situation like another ongoing case in Washington, where the Department of Justice is seeking the sale of Google’s Chrome browser to combat its online search monopoly.

In the ad tech case, the U.S. Department of Justice is pushing for the sale of Google’s Google Ad Manager, a key tool in the company’s ad server and ad exchange operations.

Google’s publisher ad servers help websites store and manage ad inventory, while ad exchanges enable content creators to sell those ads. These tools, integral to how ads are sold across the internet, have raised antitrust issues.

Earlier this year, Judge Brinkema ruled that Google had violated antitrust laws by linking its ad exchange with its ad server, a practice that stifled competition and harmed publishers. She acknowledged that this anti-competitive conduct was detrimental not only to publishers but also to the global online ecosystem, ultimately affecting users.

Despite this, Google argues that breaking up its ad tech business is not the right solution, claiming that such a move could hurt innovation and consumers alike.

The company’s defence rests on the assertion that users continue to choose Google because it provides a better product, not because of coercion or unfair advantage.

They are particularly keen to avoid a scenario where they are forced to divest parts of their business, which Google believes could lead to greater harm in the long run.

Interestingly, Google has also been exploring ways to address regulatory concerns outside the United States.

It has previously considered selling its ad exchange in order to satisfy antitrust regulators in Europe, underscoring the broader international nature of the competition cases it faces.

“We won half of this case and we will appeal the other half,” said Lee-Anne Mulholland, Google’s vice president of Regulatory Affairs.

That “other half” carries weight. On Thursday, U.S. District Judge Leonie Brinkema ruled that Google “willfully acquired and maintained monopoly power” in two critical markets: publisher ad servers and ad exchanges—key infrastructure that powers how digital ads are bought, sold, and delivered across the web.

According to the ruling, Google’s control wasn’t just strong—it was illegal. The court found that the company’s tactics, particularly tying the use of its ad exchange to its ad server, locked out competitors and harmed not just rival firms, but publishers and consumers. 

“In addition to depriving rivals of the ability to compete, this exclusionary conduct substantially harmed Google’s publisher customers, the competitive process, and, ultimately, consumers of information on the open web,” Brinkema wrote.

The ruling has set off a chain of consequences. The U.S. Department of Justice is now pushing for a radical solution: a breakup. Specifically, it wants Google to sell off its Google Ad Manager, the umbrella under which both the ad server and exchange operate.

This is the second time in under a year that a U.S. court has declared Google a monopoly—first in search, and now in ads. What makes this one particularly potent is that it hits a core part of Google’s business model: advertising revenue. 

And while the financial impact of this ruling may not shake the company’s bottom line immediately—Google’s shares only dipped 1.4%—the structural risk is enormous.

A second trial is expected, though a date hasn’t been set. That hearing could determine the full extent of penalties, including which assets Google may be forced to spin off to restore competition.

The DOJ’s case argued that Google used classic monopoly-building tactics: buying rivals, locking in clients, and manipulating how ad transactions happened.

While Brinkema cleared Google of wrongdoing related to past acquisitions like DoubleClick and AdMeld, she firmly rejected the company’s defence of its publisher tools.

Still, Google is holding its line. “Publishers have many options and they choose Google because our ad tech tools are simple, affordable and effective,” Mulholland said. The judge’s findings, however, suggest that those “choices” may not have been as free as the company claims.

The ruling has drawn praise from regulators and lawmakers. U.S. Attorney General Pamela Bondi called it “a landmark victory in the ongoing fight to stop Google from monopolising the digital public square,” adding, “This Department of Justice will continue taking bold legal action to protect the American people from encroachments on free speech and free markets by tech companies.”

Outside the courtroom, market analysts are watching closely. Michael Ashley Schulman, chief investment officer at Running Point Capital, described the ruling as a “major inflection point” for the broader tech industry. 

He warned that it could “increase regulatory risk premiums across major tech stocks,” especially those with tightly integrated services like Amazon and Meta.

Those companies aren’t off the hook either. Meta is currently in court over alleged dominance in personal social networking. Apple and Amazon are facing similar battles over control of mobile ecosystems and online retail.