The United States Department of Justice has proposed that Google, a subsidiary of Alphabet Inc., divest key parts of its advertising business, including its AdX marketplace and DoubleClick for Publishers ad server.

This recommendation follows a federal judge’s finding that the tech giant illegally monopolized two key segments of the online advertising technology market.

The judge, after hearing arguments from both sides, set a trial date for September and is now considering potential remedies to curb Google’s dominance in tools used by online publishers.

In a court filing made public Monday, the DOJ argued that structural remedies, including breaking up parts of Google’s ad tech business, are essential to restoring fair competition in the ad exchange and publisher ad server markets.

Google, however, has pushed back, stating that it supports certain behavioral changes—such as allowing real-time bids from competitors—but maintains that the DOJ’s demands for divestiture are legally unfounded.

“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,” said Lee-Anne Mulholland, Google’s Vice President of Regulatory Affairs, in a statement to Reuters.

AdX serves as a digital marketplace where publishers offer unsold ad space to advertisers in real time. Publisher ad servers like DFP help websites manage and store their digital advertising inventory, enabling content providers such as news outlets to monetize their platforms.

Google previously proposed selling AdX to settle an antitrust investigation by the European Union, but the offer was rejected by European publishers, who considered it insufficient.

The upcoming U.S. trial could have significant implications for the structure of Google’s advertising empire and the broader online advertising ecosystem.