Ad Groups Omnicom, WPP See Strong Earns  NEW YORK (Reuters) - Global advertising titans Omnicom  &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=OMC.N target=/stocks/quickinfo/fullquote"&gt;OMC.N&lt;/A&gt; and WPP &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=WPP.L target=/stocks/quickinfo/fullquote"&gt;WPP.L&lt;/A&gt; &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=WPPGY.O target=/stocks/quickinfo/fullquote"&gt;WPPGY.O&lt;/A&gt;on Tuesday reported  third-quarter results that outpaced analyst expectations,  sending shares higher on improved confidence in the ad  industry.