THE RECENT ACQUISITION of GGT Group by US global marketing services conglomerate Omnicom puts the American marketing services titan in the vanguard of UK direct marketing agency sector. Not only is GGT Direct now within its fiefdom but, according to Marketing magazine, Omnicom either owns or has major stakes in ten UK dm shops, accounting in aggregate for 17% of all British direct marketing agency business. It controls outright WWAV Rapp Collins, the UK's largest direct marketing specialist, and also has an interest in number two in the league table, Barraclough Hall Woolston Gray, via its stake in Abbott Mead Vickers BBDO.