UPDATE 1-WPP like-for-like Q3 net revenue down 8.7 pct

OMC.N) saw a 10.7 percent decline in the third quarter as key clients cut back on ad spending, Publicis (PUBP.PA) reported organic sales down 7.4 percent, and Interpublic (IPG.N) posted a 14.2 percent fall. (Reporting by Kate Holton) © Thomson Reuters...