The board has begun a tendering process before drawing up a shortlist of agencies to pitch against the incumbent during the summer.
Media planning and buying, which is handled by MindShare and Media Insight, will also form part of the review process that takes place every three years.
Roger Pride, the WTB marketing director, who has led the initiative to restore a Welsh tourist industry decimated by the foot-and-mouth epidemic three years ago, will oversee the pitch. Last year, visitor spending grew by 20 per cent between January and August.
Meanwhile, Godiva International, which is owned by the Campbell Soup Company, has picked HHCL/Red Cell to relaunch the luxury chocolate brand in the UK, European and Japanese markets. The advertising will begin with a print campaign, set to break in the summer.