Many analysts reacted immediately to the megamerger by hailing it a cure to the nagging thorn in Maurice Levy's side—the search for a successor to the 71-year old Publicis Groupe CEO, who's been overseeing the company for more than two decades.
But Omnicom Group CEO John Wren doesn't feel like the answer as much as a stopgap.
For one thing, Mr. Wren is 60. On a call with analysts last week it was disclosed that he plans to move into the chairman role after a period of five years. For a company like Publicis that's only had two real leaders since its beginnings in 1926, Mr. Wren's installment may buy just enough time to identify or train a qualified leader to see the merged company into the future.
By the time Mr. Levy moves into the chairman post in 30 months and Mr. Wren takes over as sole CEO, Mr. Wren likely will have chosen his own successor.
"They have created breathing space, because the problem is solved in the short to medium term," said Richard Pinder, CEO and co-founder of independent agency The House Worldwide, was chief operating officer of Publicis Worldwide from 2006 to 2011. "Shareholders are not going to be asking the [succession] question for five years, which will allow time for people to emerge."
In recent years, four execs' names have routinely come up as possible heir-apparents at Omnicom and Publicis; the merger of the one-time rivals throws the fates of their careers into question. Will one of them ascend? Will they be patient enough to stick around to find out or will they head elsewhere? Only time will tell.
Jean-Yves Naouri: Two years ago, it seemed certain that Publicis Groupe's chief operating officer, Mr. Naouri, would be the third CEO in Publicis Groupe's history. But shoo-in status is gone, especially he's Mr. Levy disclosed in a conference call last week that Mr. Naouri wasn't in the tight circle initially consulted about the deal -- which included supervisory board chair Elisabeth Badinter.
Andrew Robertson: The BBDO CEO is highly competent and in a powerful position. If he chooses to keep running one of the biggest creative agency networks in the world—something for which he's very well-compensated—nobody would stop him. But he's also well-equipped to make a jump elsewhere in adland or even possibly to the client side. And if he doesn't see a clear line to the top following the merger, he could be more inclined to explore new job possibilities.
Arthur Sadoun: In his early 40s, Mr. Sadoun, the president-CEO of Publicis France and managing director of Publicis Worldwide, is young and relatively inexperienced. But he has stature, figuratively and literally (he's incredibly tall). He and his wife, TV personality wife Anne-Sophie Lapix, are prominent in France, but his ability to rise within the group depends on how he does with more global duties, having recently been given responsibilities for other parts of Europe. He has time to be trained, and the big test will come if they give him the COO job.
Randall Weisenburger: Still in his early 50s, Omnicom's chief financial officer won't be looking to retire anytime soon. Once considered a potential Wren successor, now the question is whether he'll win the CFO spot over Jean-Michel Etienne, a former PWC auditor who's been CFO at Publicis Groupe since 2000. Mr. Etienne has ushered through a string of big deals, including the acquisitions of Saatchi & Saatchi, Digitas and Razorfish. Mr. Weisenburger, meanwhile, made his value clear steering while Omnicom through Chrysler's bankruptcy. He's also a good friend of Mr. Wren (their children attended the same school in Connecticut). While it's hard to imagine a spot couldn't be found for him, his chances of being CEO seem less likely.
Contributing: Emma Hall