Google’s monopoly ruled illegal, but its ad business stays

Google has avoided one of the biggest penalties it faced in its advertising antitrust battle.

Though US District Judge Leonie Brinkema sided with the Justice Department last year that Google’s ad business operated as an illegal monopoly, she ruled yesterday that the tech giant will not be required to sell its online ad exchange.

The move could have significantly changed how its advertising business operates.

The Justice Department wanted the exchange sold after accusing Google of using its dominant position to disadvantage rivals and influence how digital ad auctions worked.

Brinkema declined to break up Google but imposed other measures to curb its grip on publisher ad tech. The full remedy order is currently being kept private while Google and the government review it for possible redactions. The details are expected to emerge after 14 days.

The court found that Google had illegally restricted publishers from using competing exchanges, but it did not find the same level of wrongdoing in the tools the company provides to advertisers.

Three years ago, the DOJ and 17 states sued Google alleging that tying its ad server to its ad exchange gave the company an anti-competitive grip on the digital advertising market. The DOJ put Google’s global ad-server market share at 91%.

Despite siding with the DOJ in 2025, Brinkema rejected a forced sale of the ad exchange.

Google’s advertising business remains enormous. US ad revenue is expected to reach about $101 billion in 2026, with display advertising accounting for roughly $17 billion.

The ruling follows Google’s other major antitrust battles involving search and its Play Store.

Last year, a district judge found Google’s dominance of online search illegal but decided not to make the company sell Chrome, partly because AI could upend the search market anyway.