WPP's Ogilvy & Mather unit just announced today it has acquired a 33.3% stake in DTDigital, one of Australia's largest digital agencies. Terms were not disclosed. Ogilvy said DTDigital is part of STW Group, and that its annual revenues grew from $1 million in 2003 to a forecast of $14 million for 2012. The Melbourne-based shop has a staff of 110.