Publicis Groupe is the "outlier" among the big holding companies' third-quarter results after posting organic growth of just 0.7%.
The owner of Saatchi & Saatchi and Starcom Mediavest Group reported a 33% year-on-year rise in revenue to €2.3 billion ($2.5 billion).
But Ian Whittaker, head of European media research at Liberum, said he was concerned by its limited organic growth.
He said: "The one [holding company] that stood out in terms of disappointment is Publicis Groupe.
"It is hard to know what is going on but, looking at the numbers, it is far worse than the other players in the market."
Maurice Lévy, the chairman and chief executive of Publicis Groupe, attributed the sluggish figures to "an unusually large number of clients downsizing their accounts and postponing or even cancelling campaigns."
Omnicom’s worldwide revenue dropped by 1.1% to $3.7 billion, compared with the same period last year, but grew organically by 6.1%.
Havas posted organic growth of 5.5% and a 15.4% increase in revenue in the third quarter to €516 million ($563 million).
Interpublic’s revenue was up 1.3% year on year to $1.9 billion, including organic growth of 7.1%.
WPP’s revenue for the three months ending Sept. 30 grew 5.9% to £2.9 billion ($4.5 billion). Like-for-like revenue was also up, by 4.6%, and net sales by 3.3%.
This article first appeared on campaignlive.co.uk.