Google experts tell the US DOJ selling its ad tech business would be impossible

What you need to know

• Closing arguments wrapped Nov. 21 in the remedies trial for the U.S. DOJ's case concerning Google's ad tech business.
• A federal judge is mulling how to remedy Google's two ad tech monopolies following an April 2025 decision.
• Google is arguing a breakup of Google Ad Manager may be technologically impossible.

Google has faced multiple antitrust inquiries over the past few years, and in April 2025, U.S. District Court Judge Leonie Brinkema ruled that it has two illegal monopolies in the advertising technology business. Last week, the remedies trial in the case came to an end, and Brinkema will soon decide whether to order Google to sell off part of the ad tech business, including a breakup of Google Ad Manager.

The U.S. Department of Justice is trying to force a sale of Google's ad marketplace platform, AdX, as reported by Reuters. While the publication notes the federal judge overseeing the case said "time is of the essence," she also acknowledged how Google's planned appeals could complicate things.

"The kind of request you are making most likely would not be as easily enforceable while an appeal is pending," Brinkema told the DOJ following closing arguments in the remedies trial.

Google not only sees a forced sale of part of its ad tech business as too extreme of a measure, it also is arguing it is technically impossible, according to a blog post. "Testimony showed that the DOJ’s proposal to break up Google Ad Manager is unworkable and would create significant uncertainty and disruption for advertisers and publishers," wrote Le-Anne Mulholland, Google's vice president of regulatory affairs, in the blog post.

The company called various experts to testify as to how a breakup of Google's ad tech business could be impossible to implement. One expert, Google Professor Jason Nieh, said the decision would be a "highly complicated software engineering undertaking, with … no guarantee of success."

On the other hand, Matthew Huppert, the DOJ attorney, argued that the breakup would be the only way to achieve a "brighter, more competitive future for the open web."

Now, Brinkema will decide how to remedy Google's two illegal ad tech monopolies, considering the arguments from the company and the U.S. DOJ.