Can the EU Still Break Up Google?

A United States judge has rejected a breakup of Google in the company’s second antitrust case in the US, this time regarding its dominance in advertising technology on the open web. On Sept.2, Judge Leonie M. Brinkema, who sits on the US District Court for the Eastern District of Virginia, issued a sealed remedies decision favoring behavioral remedies over the structural divestitures sought by the US Department of Justice (DOJ). The 106-page decision was released on Sept. 16.

The ruling puts the US and European Union on potentially divergent paths. The European Commission has been investigating Google’s ad tech monopoly since 2021, in a case that overlaps substantially with US litigation. The Commission has previously indicated that structural remedies, including divestiture, could be necessary to address Google’s conflicts of interest.

Now that the US has rejected a breakup, can the EU still pursue one — and would an EU-only remedy be technically and legally feasible?

The US rejects a breakup

The case was brought by the DOJ in 2023, accusing Google of “monopolizing multiple digital advertising technology products in violation of Sections 1 and 2 of the Sherman Act.” The case examined Google’s position across the ad tech stack, including publisher ad servers (DoubleClick for Publishers), advertiser tools (Google Ads) and the exchange that matches buyers and sellers of online advertising (AdX). The court ultimately found Google had illegally maintained monopoly power in the publisher ad server and ad exchange markets, but rejected the government's claim concerning the advertiser ad network market.

The investigation specifically looked at how Google acquired competitors in a strategy to obtain control over key digital advertising tools used by website publishers to sell advertising space. Google’s 2008 acquisition of DoubleClick was central to the DOJ’s case because it brought together key parts of the ad tech stack under one company, helping Google establish control over publisher ad servers, ad exchanges and related advertising tools.

The DOJ alleged that Google effectively tied access to its advertiser demand and AdX to DoubleClick. Brinkema ultimately found that Google unlawfully tied its publisher ad server and exchange and used that tie to maintain its monopoly power. Later, during the trial, witnesses testified “that publishers simply had to be on [DoubleClick for Publishers] because it was the only way to fully access the large base of advertisers in Google’s ad network through Google’s AdX exchange.”

Following the trial, the judge ruled that Google had illegally maintained a monopoly over two parts of the online advertising market, the publisher side and the exchange, though dismissed arguments concerning the advertiser side, “saying the government had failed to prove that it constituted a real and defined market.” Following the ruling, each side had to make proposals for how to remedy the monopoly.

Behavioral remedies instead of divestiture

The DOJ was seeking a breakup of the company, forcing divestitures of Google’s ad exchange and its publisher ad server, which would become open source and run by an independent body. The DOJ also included other remedies, such as creating an escrow account funded by Google, alongside behavioral remedies such as interoperability with rival ad exchanges and better pricing transparency mechanisms for publishers and advertisers. Google, while opposing structural remedies, also put forward behavioral remedies.

In a 106-page decision unsealed on September 16, 2026, the judge imposed the behavioral remedies, though stating that a breakup of Google’s ad tech business was “neither realistic nor needed.” To undo Google’s policies that tie DoubleClick to AdX, the judge has ordered Google to make its services interoperable with rivals, meaning that Google will need to integrate AdX and DoubleClick with Prebid, the main provider of header bidding.

Header Bidding is a technique whereby websites insert a piece of JavaScript code into the header section of their webpages, which routes the website’s ad space to multiple exchanges before passing inventory to Google. This technique has existed since 2014, though its capacity to threaten Google’s dominance has been limited for multiple reasons, including Google’s Unified Pricing Rules, “a price parity condition prohibiting publishers from routing their ads through Google’s exchange at prices higher than they route them through competing exchanges,” which posed another significant restriction on header bidding. The DOJ uncovered that the pricing condition was explicitly to undermine header bidding as a competitive threat.

The judge has additionally ordered Google “to deprecate and not reimplement Unified Pricing Rules in DFP for all indirect transaction types,” thus encouraging alternative exchanges to better compete. Google will also be barred from reimplementing First Look and Last Look functionality. Google’s Last Look advantage was a mechanism where Google could see the winning bid on other exchanges, and place a slightly higher bid at the last minute. Thus, despite header bidding technically bypassing Google’s exchanges, Google’s dominance in the publisher ad server market meant that information could still pass through to its own exchange and “displace trades by a penny.” Removing these policies is intended to “restore[...] competition in the ad exchange market.”

The company must also provide publishers with “historical and configuration data” from DoubleClick, as well as ongoing AdX bid data, and must allow publishers to export that data to rival publisher ad servers. It is also prohibited from engaging in discriminatory bidding behavior, with specifics still to be worked out between Google and the DOJ.

However, Google ads “will be prohibited from favoring Google-owned or Google-affiliated ad tech tools when bidding for indirect open-web display ad inventory,” and Google’s use of first-party data (generated from services like YouTube) will be regulated “when bidding for indirect open-web display ad inventory.” This recognizes the information asymmetry that favors Google due to its vast ecosystem. Finally, Google must also appoint an internal monitor to track its compliance.

Brinkema's decision therefore rests partly on the view that Google's ad tech stack is too integrated for divestiture to be a practical remedy. That creates a particular problem for the EU. Its investigation covers similar conduct, but Brussels has not abandoned the possibility of a structural remedy.

Brussels faces a difficult choice

Most of the investigated abuses are mirrored in the case brought by the European Commission in 2021. The Commission alleges that Google has favored its own ad tech services to the detriment of potential competitors, and fined the company €2.95 billion for abusing its dominance in ad tech in 2025. The Commission gave the company 60 days to resolve its conflict of interest and stop preferring its own ad exchange, though warning that structural remedies were likely to be pursued. Euractiv reported that Google submitted a proposal to resolve the Commission’s concerns last November, but the Commission extended the deadline.

Despite the convergence of the two cases, the US administration threatened economic retaliation if another jurisdiction attempted to penalize American companies. The Commission allegedly delayed the fine due to fear of tariffs and restrictions imposed by the Trump administration. Competition chief Teresa Ribera had continued to be bullish on maintaining its course, stating that “it appears that the only way for Google to end its conflict of interest effectively is with a structural remedy, such as selling some part of its Adtech business,” and that the Commission “will continue to apply our rules firmly and fairly, without fear or favor, in relation to all companies operating in Europe.”

However, now that the US has changed its course, Ribera has stated that the EU “should try to stay consistent with authorities elsewhere.” Meanwhile, other members of the parliament have reportedly urged the Commission “to preserve the option of structural remedies against Google, and that Brussels should not necessarily follow the approach taken by a US court.” The question remains whether it is feasible for the European Commission to go beyond the US ruling and impose structural remedies, both technically and politically.

Can Brussels go farther?

There are various conflicting factors at play. First, it is significant to note that EU law has strict proportionality standards for imposing structural remedies, making breakups rare. The EU also has less experience imposing such remedies compared to the US, despite potential limitations of the US courts-based procedure.

Second, the director general of the Commission’s competition department has indicated that the case itself is difficult, involving “businesses that have already been fully integrated following an acquisition,” separation of which being “difficult to implement.” Google has long been dominant throughout the ad tech stack, since its acquisition of DoubleClick in 2008. The parts of the stack no longer work as independent entities and have long been tied and bundled together.

In the unsealed judgment, Brinkema echoed this, concluding that the stack is too integrated and a divestiture would cause too much “uncertainty” regarding its future functionality, arguing that it “is especially concerning because the stakes are high: this is ‘technology that absolutely has to work for customers’.”

However, technical difficulty is exacerbated in the case where the two jurisdictions depart. For one, as explained by Jacob Parry, reporting for Politico, Google’s “buying tools, selling tools and the exchange between them run as one global system. A sale ordered by Brussels would apply on one side of the Atlantic, in a market where the largest advertisers and publishers don’t stop at the EU’s borders.” Arielle Garcia, chief operating officer of Check My Ads, a US-based watchdog, told Politico “that while a Europe-only remedy might be technically possible, its effect would be minimal.”

Parry reported that “several people involved in the complaint said privately that they no longer see a viable way to carve out and sell part of a US company’s business within Europe alone, and are now pushing for the strongest measures the Commission can realistically deliver.”

Max Bank, EU Competition Lead at Rebalance Now, in a statement to Tech Policy Press, agreed that a breakup order in the EU is less likely, though rejected the notion that a breakup would be technically complicated, and puts this down to political will. An EU-only structural remedy could also create additional friction with Washington, which has already threatened trade action in response to EU measures against US technology companies. The threat is real; the US is the EU’s biggest trading partner, generating roughly €1.77 trillion in value in 2025.

Tim Cowen, the Chair of the Antitrust Practice at Preiskel & Co, told Tech Policy Press that while divestiture can be successful, the case calls for close attention to how different stakeholders, advertisers and publishers, can access alternatives, which may not necessitate a breakup. He emphasizes the need to restore competing alternatives by “empowering” the advertiser to bypass Google.

“AdX isn’t anything special; it is just a connector,” he adds, pointing to header bidding as providing a “competitive pathway” to restoring “competing alternatives.” This largely aligns with what Brinkema has ultimately ruled.

Considering the behavioral remedies that have been imposed, data access may be a welcome intervention, as publishers may get “a clearer window into how their ad space is really being priced.”

Google has long been in a position to hide what prices win ad auctions, and how much of a cut the company takes. Additionally, the mandates imposed by Brinkema to promote alternative exchanges, such as header bidding, may help end the unfair advantage held by AdX. Such remedies may be deemed sufficient by the Commission to end its allegations of self-preferencing by Google.

The Commission has no strict deadline to act, though Ribera has signaled that she will pay attention to Brinkema’s final decision.

The US ruling does not legally determine what Brussels can do, but it removes an important point of coordination between the two jurisdictions. The Commission therefore faces a choice between pursuing structural remedies against a business that a US court has deemed too integrated to break up and testing whether the behavioral remedies imposed in the US can restore competition without divestiture.