The sportswear and equipment manufacturing giant kicked off a review in September with a brief to help existing customers and handle some digital activity. Campaign understands Havas Helia has been appointed after a competitive pitch against M&C Saatchi's Lida, CHI & Partners/Rapier and Proximity. Formal pitches took place in mid-November at Adidas’ headquarters in Herzogenaurach, Germany. The process was handled by Roth Observatory.