The marketing services group says revenues fell to €4.5bn (£3.9bn) in 2009, hit by the “shrinking” global advertising market.
Revenues from its European agencies dropped 9.9% on an organic basis to €1.5bn (£1.3bn).
The decline in revenues slowed to 5.4% in the fourth quarter as it “saw a steady and continuing increase” in performance in the second half of 2009.
Maurice Lévy, chairman and chief executive officer of Publicis Groupe, says it is aiming to return to positive organic growth this year.
The group restated its commitment to achieving 60% of its revenue from digital activities and emerging economies in the future. The company acquired ad agency network Razorfish from Microsoft last year.
Last week, US marketing group Omnicom reported revenues fell 12% to $11.7bn (£7.5bn) in 2009, while Euro RSCG and MPG owner Havas posted a 7.9% fall for last year.