The holding company turns in performance significantly worse than that of Publicis Groupe, as operating profit plummets 89% to $62.5 million.
Agreement may last only six months but Omnicom agencies stand to gain from priority access to data and insights.
About 3,000 executives took pay reductions of up to 20% for three months.
In rare move, Facebook founder attended meeting to assure Omnicom, Dentsu Aegis Network and Unilever as it faces growing advertiser boycott.
But diluted net income per share rose two cents, or 1.7 percent, to $1.19 compared to $1.17 for the first quarter of 2019.
A number of holding companies say they will not enter the awards, while others have yet to decide.
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