* Q3 net sales up 3 pct v forecast 3.3 pct
* Reiterates outlook and outperforms peers
* Shares flat after recent strong run (Adds reaction, shares)
By Kate Holton
LONDON, Oct 31 (Reuters) - WPP Plc, the advertisinggroup run by high-profile executive Martin Sorrell, posted aslightly lower-than-expected 3 percent quarterly sales rise,reflecting growing concerns over geopolitical tensions and aslowdown in the global economy.
The British group, owner of the JWT and Ogilvy & Matheragencies, reiterated its full-year sales target however andoutperformed its major rivals due to its broad geographicalreach and strong presence in digital advertising.
"All in all, whilst clients may be more confident than theywere in September 2008, they broadly remain unwilling to takefurther risks, particularly given multiple geopolitical flashpoints," the company said in a statement on Friday.
WPP, whose chief executive Sorrell is a frequent commentatoron business issues such as taxation, posted a 3 percent rise inlike-for-like net sales, slightly below the consensus of 3.3percent and a first half rise of 4.1 percent.
Revenue - which the group distinguishes from net sales dueto the way it books some income - was up 3.1 percent in sterlingterms at 2.76 billion pounds and on a constant currency basiswas up 10.6 percent.
WPP, which has more than 179,000 staff in 111 countries,said it expected a slowdown in the fourth quarter, afterprotests in Hong Kong, the spread of Ebola and the rise ofIslamic State in Syria and Iraq knocked corporate confidence anddeterred companies from spending freely.
WPP also faced tough comparatives in the third quarter andsaid it had seen some slowdown in North America and Britain,partly offset by a significant increase in western continentalEurope.
ORGANIC SALES
The trading update, which caused WPP's shares to stall aftera strong run in to the results, still put it ahead of its bigfour peers, among which it is the last to report onthird-quarter performance.
On an organic sales basis, including the full impact ofdigital billings, WPP was up 7.6 percent, well ahead of Frenchrival Publicis on 1 percent and also ahead ofInterpublic on 6.3 percent and Omnicom on 6.5percent.
Analysts at Citi said the third-quarter growth wasdisappointing but said investors would be reassured by theconfirmation of the full-year outlook.
"The implication of guidance is that the fourth-quarterwon't necessarily be much better," they said. "In this context,valuation does not look stretched .... but nor does it lookparticularly compelling."
WPP shares trade on a multiple of 13.4 times forecastearnings, according to Reuters data, a discount to a peeraverage of 15.5 times.
WPP also said it had secured net new business of $1.66billion in the third quarter and $5.75 billion in the first ninemonths, which it said ranked it first in net new business tablesfor the industry.
Its shares were flat at 1,210 pence by 0926 GMT, havingbounced strongly from a 16-month low of 1,091p seen in midOctober. (Editing by Neil Maidment and David Holmes)