The U.S. Department of Justice (DOJ) has proposed that Google offload its AdX digital ad marketplace and its DFP ad server platform following a federal judge’s ruling that the company unlawfully maintained monopolies in two major online advertising markets.
In a court filing late Monday, the DOJ said such measures were necessary to restore fair competition in both the ad-exchange and publisher ad-server sectors. The proposal comes after U.S. District Judge Leonie Brinkema ruled last month that Google had “willfully acquired and maintained monopoly power” in the digital ad tech ecosystem.
A trial to determine final remedies is scheduled for September.
The DOJ’s proposal marks the latest challenge to Google’s advertising dominance, following a separate antitrust ruling in 2023 that found the company held an illegal monopoly in online search.
Google, which is owned by Alphabet, has opposed the proposed sales, arguing that such structural changes go beyond legal boundaries and would disrupt the digital advertising ecosystem. “The DOJ’s additional proposals to force a breakup of our ad tech tools go well beyond the Court’s findings, have no basis in law, and would harm publishers and advertisers,” said Lee-Anne Mulholland, Google’s VP of Regulatory Affairs.
Google has instead proposed behavioural remedies, such as ensuring competitors have access to real-time bidding data. However, the DOJ maintains that only structural separation can effectively resolve Google’s dominance.
AdX is a key platform that enables publishers to auction off ad space to advertisers in real time, while the DFP platform helps websites manage and deliver ads. Together, they are integral to how online publishers monetize content.
Shares of Alphabet fell nearly 1.1% in premarket trading on Tuesday following the DOJ’s filing.
Google had previously offered to sell AdX in an effort to resolve a European Union antitrust investigation, but the proposal was rejected by European publishers who deemed it inadequate.
