PARIS (Reuters) - French advertising group Publicis said on Sunday that demand for advertising rebounded in October, as it reported more than 7 percent organic growth in group sales on strength in the United States, emerging markets and digital ads.

A contraction in September had depressed Publicis' monthly revenue by 1.6 percent compared with a year earlier and led it to post weaker than expected third-quarter sales.

Similar slowdowns hit market leader WPP and U.S.-based Omnicom in September, particularly in Europe where big advertisers hit the brakes on spending.

The chief executive of Publicis, Maurice Levy, said in an emailed statement on Sunday that it was too early to say whether October's improvement would continue through the fourth quarter because companies often adjust their marketing budgets in December.

"At this point in time, we cannot yet confirm that growth and confidence are back," said Levy. "Europe and analog media are still at worrying levels."

Market research group ZenithOptimedia, a subsidiary of Publicis, scaled back its target for growth in global advertising spending this year to 3.8 percent from the 4.3 percent it predicted in June, blaming Europe's debt crisis.

(Reporting by Leila Abboud and Gwenaelle Barzic; Editing by Leslie Adler)