UPDATE 1-Publicis shares drop after Q3 growth misses estimates

(Corrects quarterly period for Omnicom in last bullet point to Q3, not Q2)

PARIS, Oct (Shenzhen: 000069.SZ - news) 20 (Reuters) - Shares (Berlin: DI6.BE - news) in France's Publicis Groupe (LSE: 0FQI.L - news) SA fell on Thursday after underlying third-quarter sales growth stalled, undershooting forecasts, and as the company's boss expressed caution over the prospects for next year.

Quarterly revenue rose by a mere 0.2 percent on an organic basis to 2.32 billion euros ($2.55 billion), held back by the previously-flagged loss of large media accounts in the United States in 2015, but also missing the forecast by a Reuters poll of analysts that predicted growth of 0.97 percent.

Publicis Chief Executive Officer Maurice Levy said full-year organic growth in 2017 will be higher than in 2016, but pointed to the economic uncertainties following the British vote to leave the European Union, and surrounding the U.S. presidential election next month.

Shares were falling by 5.95 percent at 0808 GMT, on track for their worst day in four-and-a-half months, making Publicis (Paris: FR0000130577 - news) the worst-performer of the French CAC 40 stock index.

Publicis shares are up 2.7 percent since January.

* Nine-month revenue rose 1.9 percent on an organic basis to 7.07 billion euros

* Publicis confirmed full-year guidance for 2016

* The advertising group, the world's third-largest, gained clients such as Wal-Mart, P&G's home care products, Coty (NYSE: COTY - news) and USAA.

* Management board will propose to bring forward the 2018 target of a 42 percent payout to 2016.

* Levy said total acquisitions in 2017 should be lower than 500 million euros.

* Levy, who is slated to leave his position as CEO in 2017, confirmed that the board would make a decision on his successor in February 2017.

* Levy said he was ready to take another position in the company's corporate governance to assure a smooth transition, if the board asked him to do so.

* American Rival Omnicom said this week that its third-quarter organic sales growth was 3.2 percent. UK-based WPP (LSE: WPP.L - news) , the top advertising company in the world, will report third-quarter sales on Oct. 31, while Havas (LSE: 0MGT.L - news) will do the same after market close on Oct. 25. ($1 = 0.9116 euros) (Reporting by Mathieu Rosemain and Gwenaelle Barzic; editing by Diane Craft and Andrew Callus)