The charity, which plans to bring together its fundraising and brand activity briefs, has drawn up a longlist of shops to pitch for the merged account against Proximity London, which holds both briefs.
An initial list of Saatchi & Saatchi, BMP DDB, WWAV Rapp Collins West, Ogilvy & Mather, Proximity and Claydon Heeley Jones Mason has been cut back to Saatchis, a joint team from BMP and WWAV, and Proximity.
The UK review does not affect international creative, which is handled by Ogilvy & Mather. However, media is included in the new brief and is likely to be awarded to the group that wins creative, as Proximity Media handles it.
Tanya Reed, the WWF head of marketing and communications, said: "We've worked with Proximity for two years and it has worked on two briefs. We feel we need to leverage things by bringing the briefs together and so now was the appropriate time."