Organic growth – which factors out acquisitions, disposals and currency fluctuations – was 0.6 per cent in Europe, where revenue reached €625m (£456.8m, $707m), and 0.4 per cent in North America, where they reached €1.3bn (£950m, $1.5bn).
In Asia Pacific, sales grew 4.3 per cent organically to €260m (£190m, $294.1m), and in the Middle East & Africa growth was 6.1 per cent to €61m (£44.6m, $69m).
Latin America continued its decline, with organic growth of -7.5 per cent, leaving sales at €87m (£63.6m, $98.4m).
The UK, Russia and Mexico were among the countries in negative organic growth in the period, while organic growth in both the US and France was between zero and five per cent. Mainland China, India and the UAE had organic growth above five per cent.
Total revenue across Publicis grew 33 per cent to €2.3bn (£1.7bn, $2.6bn). Across the first nine months of 2015, digital organic growth was 4.1 per cent, with analogue organic growth of -1.2 per cent.
The holding company, which owns and operates the MSLGroup network, did not break out individual PR numbers.
Publicis said its Sapient business was back to growth in the quarter, growing by around five per cent organically. The company said it expected full-year organic growth to be around one per cent overall.
Publicis also owns ad agencies Saatchi & Saatchi and BBH.