The business moves from The Allmond Partnership without a competitive pitch. TAP has handled the account for less than two years after winning it from PHD.
Walker Media takes on the planning side of the business with immediate effect and will handle buying by 2006.
Walker Media's appointment is part of a wide-ranging review of Weetabix's activities, instigated by its chief executive, Ken Wood. Wood was hired when Weetabix was sold by the George family last year to the private equity company Hicks Muse Tate & Furst. This later became Lion Capital.
Last December, Wood held a pitch for Weetabix's creative account, which subsequently moved from FCB London to DDB London.
Wood said: "The appointment of Walker Media is the final piece in the jigsaw. We look forward to working with it and are now confident our agency roster is optimal."
Wood is a former managing director of Muller Foods and worked with Christine Walker, Walker Media's chairman, when she was the chief executive of Zenith Media.
- Comment, page 44.