The Federal Trade Commission has issued a second request for information regarding Omnicom’s proposed $13 billion acquisition of Interpublic Group of Cos., a move that could delay approval of the deal for months or ultimately lead to a lawsuit seeking to block it.

While the FTC hasn’t publicly disclosed what issues it’s seeking more information on, the commission’s lawyers have been asking about principal media buying and media company incentives to agencies, and how a bigger agency holding company might affect both media companies and brand marketers in those areas, according to people familiar with the matter.

In a statement, Omnicom and IPG said a second request is “a standard part of the regulatory process,” adding that “both parties continue to expect the transaction to close in the second half of 2025.” The agencies declined to comment on other questions posed by Ad Age. 

There’s been considerable debate about how a bigger combined agency could impact alleged “collusion” against conservative media and whether that might influence the FTC’s decision. Letters last week from five Democratic senators to Attorney General Pam Bondi and FTC Chairman Andrew Ferguson cited a recent Wall Street Journal story, raising concerns that Elon Musk is threatening to pressure the administration to block the deal if the agencies don’t spend more with X. Ferguson replied with a post on X saying “The Trump-Vance FTC will not be swayed or intimidated by [Elizabeth] Warren and her Democratic allies. We remain committed to stopping anticompetitive behavior and safeguarding American workers and consumers. We will enforce the law without fear or favor.”

Second requests for information in U.S. antitrust reviews come in only 1.5%-3% of cases, and aren’t necessarily related to the size of the deal, said Michelle Mantine, an attorney with Reed Smith who specializes in antitrust. Given the complexity of issues around principal media trading, if that’s an area of focus for the FTC, that could add months to a review, Mantine said. The FTC then has 30 days after receiving its requested information to either allow a deal to move forward or file suit to block it. Three quarters of deals subject to second requests are abandoned or modified, according to a 2022 report by the FTC. Among recent industry deals, Walmart’s acquisition of Vizio last year also got a second request for information from the FTC but was ultimately approved and closed in under 10 months.

Also read: Inside principal-based media buying

What the FTC is asking about

Two people who said that they have been interviewed by the FTC, speaking to Ad Age on the condition of anonymity, said the topic of collusion against conservative media didn’t come up. But both said FTC investigators did ask about principal media buying, in which agencies acquire and resell media to clients, and one said they also covered the related topic of media company incentives to agencies.

One of the people described the questions as similar to what investigators from K2 were asking when that private investigative firm was preparing a report on rebates and media transparency for the Association of National Advertisers in 2016. That followed a 2015 speech by former Mediacom CEO Jon Mandel at an ANA Media Conference alleging widespread rebates and undisclosed principal transactions involving agencies. Ultimately, that led to at least one Justice Department investigation, but no legal action, and the focus wasn’t on antitrust issues.

Among the issues this person interviewed by the FTC said came up were whether a larger agency holding company might have greater leverage to get better exclusive deals, such as for or related to NFL telecast buys.

The FTC appeared to focus on the effect the Omnicom-IPG deal would have on the biggest advertisers, Fortune 500 companies that tend to be the mainstay of agency holding companies, rather than the broader “long tail” market of smaller marketers that may use independent shops or self-service buying tools.

Another person who said that they have been interviewed by the FTC said questions included whether principal media buying results in any restriction of choice in the agency pitch process, whether the money agencies are able to bargain away from media companies means more journalists get fired and less programming for minorities or kids, and ultimately how this might affect clients.

Growing scrutiny of principal media

The FTC’s questions come as principal media trading has become a hotter topic in the U.S. over the past year. That includes controversy over the Amazon media review and other retail media account reviews, in which agencies allegedly have agreed to increase the amount of the account holders’ retail media they sell to their other clients in order to win the retailers’ media business.

The biggest leverage impact from a bigger agency holding company would appear to be on media companies, but creating a bigger agency holding company also could have substantial effects downstream.

“There are huge downstream consequences,” said a lawyer who works in the ad industry and spoke on the condition of anonymity. While an Omnicom-IPG merger might not have much effect on Publicis Groupe or WPP, it could squeeze business of smaller players, the lawyer said, adding that it might advantage bigger marketers and publishers to the detriment of smaller ones.

One area of exclusive offers linked to principal buying is early access to new tech tools, such as AI capabilities, bundled with media among tech companies that sell both, according to people familiar with the matter. Conceivably, a bigger agency would have more leverage to get such deals, which in turn might increase leverage with clients who otherwise would resist opting into principal media deals, the lawyer said.

Principal deals, and the free or reduced cost inventory or other incentives that help fuel them, are mainly limited to the biggest agency holding companies, the lawyer said. “The big get bigger and the small get screwed. It’s harder for the large agencies to serve smaller clients. So it’s not just that the smaller agencies lose and the small publishers lose. The small clients lose too because they can’t get any of that.”

Contributing: Lindsay Rittenhouse