ONE OF THE WORLD’S less exciting agency groups, US-owned global network Leo Burnett, has driven the thin end of an estimated £25m wedge into one of the planet’s sexiest ad shops - London-based Bartle Bogle Hegarty, creator of high profile campaigns for Levi-Strauss, Polaroid, Coca-Cola and Lego. Privately owned BBH is to sell 49% of its stock to the US giant, purportedly because it needs 'the right partner to help us develop internationally'. Although the two agencies have yet to agree how to 'maximise resources', BBH will set-up a standalone media venture in the Asia-Pacific region next year to service the needs of its clients; while Burnett will continue its media buying activities on a market-by-market basis. Neither company has representation on the other’s board and BBH insists it will remain independent. [Marketers who believe this are invited to attend a special meeting in the telephone kiosk at Groucho’s on Christmas day.]