** Shares in WPP WPP.L up 3% at 275.8p
** Advertising group is preparing to bring its three main creative advertising agencies under one banner as part of a streamlining push, FT reports
** WPP will set up new holding structure called "WPP Creative", report says, citing three people familiar with plans
** WPP did not respond to Reuters' request for comment
** Up to last close, stock had fallen ~21% this year
(Reporting by Prerna Bedi in Bengaluru)
((Prerna.Bedi@thomsonreuters.com ; +91 98052 24616))