ALEXANDRIA, VIRGINIA — US District Judge Leonie Brinkema ruled on September 3, 2025, that Google will not be required to sell its AdX advertising exchange in the antitrust case United States v. Google LLC. Instead of ordering a structural breakup, the court accepted behavioral remedies proposed by the parties to restore competition in the digital advertising market.

The underlying lawsuit began in 2023 when the US Department of Justice and a coalition of states sued Google over its dominance in advertising technology markets. The case centers on the financial mechanics of online advertising, where publishers pay Google a 20 percent fee to sell ads in auctions on AdX. Google stated that the technology underlying its advertising exchange handles 55 million requests per second.

The court order and full opinion are sealed for 14 days to allow the parties to request redactions. The parties have 30 days to submit a joint proposed final judgment.

Google Vice President of Regulatory Affairs Lee-Anne Mulholland welcomed the decision in a statement. "We’re very pleased the Court rejected the DOJ’s proposal to break apart tools that help small businesses reach new customers and grow," Mulholland said. Despite avoiding a forced sale of AdX, Google plans to appeal the underlying liability ruling from April.

Sacha Haworth, Executive Director of a consumer advocacy group, criticized the outcome in an interview. "It takes an Olympic level of mental gymnastics to find that Google is operating an illegal monopoly and then decide to do nothing about it," Haworth said. She added that the ruling sends a problematic signal to the industry.

"With Big Tech continuing to suffocate new and innovative businesses from gaining traction, Judge Brinkema, like (U.S. District Judge Amit) Mehta before her, is sending the wrong message at the wrong time," she said. The Department of Justice stated it is evaluating appropriate next steps regarding the case.

Why It Matters

The ruling determines the structural future of Google's advertising technology stack, which processes billions of dollars in transactions annually. By rejecting the forced sale of AdX, the court opted for behavioral fixes rather than breaking up the company's integrated ad tools. This decision affects how publishers and advertisers interact with Google's platforms, particularly given the 20 percent fee publishers pay to use AdX. The acceptance of behavioral remedies suggests the court believes competition can be restored without dismantling the existing infrastructure.

The case represents a major test of federal antitrust enforcement against dominant technology firms. The US Department of Justice and state coalitions sought to dismantle what they described as illegal monopolies in ad tech markets. The sealed nature of the current opinion limits immediate public understanding of the specific liability findings and the rationale for accepting certain behavioral measures. Future legal actions will depend on the joint proposed final judgment submitted within 30 days and any appeals filed by Google or the government.

Timeline

In 2020, Ad Manager represented 4.1 percent of Google’s overall revenue and 1.5 percent of operating profit. The US Department of Justice and a coalition of states sued Google in 2023 over its dominance in advertising technology markets. In April 2025, Judge Brinkema ruled that Google held illegal monopolies in the markets for publisher ad servers and ad exchanges.

During that same period, the court found that Google unlawfully tied its publisher ad server, DoubleClick for Publishers (DFP), to its AdX ad exchange. The court also found that Google did not illegally monopolize the market for advertiser-side tools. On September 3, 2025, US District Judge Leonie Brinkema ruled that Google will not have to sell its online advertising exchange, AdX. Also on September 3, 2025, Sacha Haworth stated, "With Big Tech continuing to suffocate new and innovative businesses from gaining traction, Judge Brinkema, like (U.S. District Judge Amit) Mehta before her, is sending the wrong message at the wrong time." She further remarked on that date, "It takes an Olympic level of mental gymnastics to find that Google is operating an illegal monopoly and then decide to do nothing about it."

What's New

Later reporting confirmed that publishers pay Google a 20 percent fee to sell ads in auctions on AdX. Additional details revealed that Google stated the technology underlying its advertising exchange handles 55 million requests per second. Further coverage included the statement from Lee-Anne Mulholland: "We’re very pleased the Court rejected the DOJ’s proposal to break apart tools that help small businesses reach new customers and grow." Reports also reiterated that the US Department of Justice and a coalition of states sued Google in 2023 over its dominance in advertising technology markets. It was also reported that Google generates nearly US$400bil in annual ad sales. Additional context confirmed that the court found that Google unlawfully tied its publisher ad server, DoubleClick for Publishers (DFP), to its AdX ad exchange. Critic Sacha Haworth provided further comment, stating, "With Big Tech continuing to suffocate new and innovative businesses from gaining traction, Judge Brinkema, like (U.S. District Judge Amit) Mehta before her, is sending the wrong message at the wrong time." She also said, "It takes an Olympic level of mental gymnastics to find that Google is operating an illegal monopoly and then decide to do nothing about it."