Washington: Publicis Groupe SA’s merger with Omnicom Group Inc. is seen by antitrust experts as likely to draw intense scrutiny and may even be blocked by US regulators.

The transaction, which culminates years of consolidation in the global advertising market, is likely to spark opposition from corporate customers concerned about the power the merged firm may wield in the advertising market, according to Bert Foer, president of the American Antitrust Institute, which advocates strong enforcement of antitrust laws.

“The merged firm is going to be able to influence strategy for an entire industry," Foer said in a phone interview. “They will have a unique ability to tell clients, ‘Here’s what you need to do,’ and an enhanced ability to coordinate strategies such as when to introduce new products, how to price them and how to market them."

If approved, the merger of Paris-based Publicis and New York-based Omnicom will overtake market leader WPP Plc and create an advertising powerhouse with $35 billion in market value and about 41% of total spending by the top 10 media agencies in the world, according to data compiled by Advertising Age.

Allen Grunes, an antitrust lawyer with GeyerGorey LLP in Washington, said the transaction may be the one that hits resistance from antitrust regulators after years of consolidation in the industry.

Reduced Competition

Efforts by the companies to highlight the benefits to consumers of cost savings from the deal may not be enough to outweigh arguments that the merger could hurt consumers because of reduced competition in the advertising market, Grunes said.

“I don’t see an effective efficiencies theory and if there are complainants they may come up with an effective theory of harm," Grunes said. “I don’t see this being solved by divestitures either, so all of this makes me say this may be one deal too many."

The alliance will bring under one roof agencies including Omnicom’s BBDO Worldwide and Publicis’s Leo Burnett and Saatchi & Saatchi, extending their presence in every major market. If approved, the transaction is expected to be completed by the first quarter of 2014.

Chief executives of both companies said at a press conference announcing the merger on Sunday they didn’t expect to face regulatory hurdles.

US Review

It isn’t clear which of the two US antitrust agencies, the Federal Trade Commission or the justice department’s antitrust division, is going to review the merger. The agencies usually agree which will review a transaction based on a clearance process that awards the responsibility to the agency with the most expertise.

Gina Talamona, a justice department spokeswoman, and Peter Kaplan, a Federal Trade Commission spokesman, declined to comment on the merger.

“I’m not so sure there’s an antitrust problem," Robert Doyle, an antitrust lawyer with Doyle, Barlow & Mazard PLLC in Washington and a former US Federal Trade Commission official, said in a phone interview. “If a big corporate client like Pepsi thinks it’s getting taken advantage of, it will find someone else."

Large corporate clients that use advertising services aren’t likely to let the merged firm dictate rates, Doyle said .

“They can easily go to second-tier firms and cobble together an international presence," Doyle said. “There is no significant market power here, no barriers to entry."

Doyle said he expected the Publicis-Omnicom review to go to the justice department’s antitrust division.

Advertising Growth

Publicis, Omnicom and London-based WPP, led by Martin Sorrell, have grown through consolidation over decades as they vie with each other for accounts. Global ad spending will probably rise 5.1% next year, accelerating from 3.5% in 2013, according to ZenithOptimedia, a researcher that’s part of Publicis. Growth may reach 5.8% in 2015, ZenithOptimedia said.

Jonathan Kanter, an antitrust lawyer with Cadwalader, Wickersham & Taft LLP in Washington, said he expects the transaction to get a very close look from antitrust regulators. He said “it won’t be an easy task" for the reviewing agency to come up with a theory of harm in such a complex and fragmented industry “where the subsidiaries of the merged company often compete with each other for business." Bloomberg

Kristen Schweizer in London and Marie Mawad in Paris contributed to this story.