Alphabet’s Google is set to go on trial this September in a major antitrust case brought by the U.S. Department of Justice (DOJ), which seeks to force the tech giant to divest parts of its advertising technology business. The trial, scheduled by U.S. District Judge Leonie Brinkema in Alexandria, Virginia, will focus on the DOJ's proposals to address Google’s dominance in digital ad infrastructure.

The DOJ aims to compel Google to sell off its ad exchange and publisher ad server operations—two critical components that power the buying and selling of digital ads across the internet. The move is part of a broader remedy to dismantle what the DOJ views as an unlawful monopoly harming online publishers, advertisers, and ultimately internet users.

“This remedy would take years,” said DOJ attorney Julia Tarver Wood, referring to the structural separation they plan to argue for in court. The DOJ is expected to file its detailed proposal on the remedy this Monday, alongside Google’s formal response.

Google, however, is resisting calls for a divestiture. Company attorney Karen Dunn argued that structural remedies—such as forced divestments—are both unnecessary and potentially illegal. Instead, she said Google is open to behavioral remedies that would give rival companies better access to real-time ad bidding and other core features.

Dunn further warned that forcing a sale of its ad tech units could have unintended consequences, including harming users and facing limited buyer interest due to the specialized nature of the tools.

The legal backdrop to the trial stems from an April ruling by Judge Brinkema, who found that Google had unlawfully tied the use of its ad exchange to its publisher ad server, effectively limiting competition. Brinkema described Google’s practices as anticompetitive and harmful to both publishers and users, saying the company's policies were “not in its publisher customers’ best interests.”

Publisher ad servers are essential tools that allow websites and online platforms to manage and sell their ad inventory. Combined with ad exchanges, these systems form the backbone of modern digital advertising.

This is not the first time Google has considered divesting its ad tech business. In 2023, Reuters reported that Google had explored selling its ad exchange unit to address concerns raised by European antitrust authorities. Now, the company faces similar pressure on its home turf.

The outcome of the September trial could have wide-ranging implications for the digital advertising industry and how big tech companies operate in increasingly scrutinized markets.