The agency will handle all consumer and trade PR for the brand, including a number of brand initiatives and new product development launches.
Established in 1991, Green & Black's joined Cadbury in 2005. The brand is known for its ethically sourced, premium chocolate and was the first UK brand to earn a Fairtrade mark.
Previously, Green & Black's worked with Phipps PR on a global and UK basis. Phipps will continue to retain its global business.
The agency will report to Green & Black's senior brand manager Gemma Barton and brand manager Anita Kinniburgh. The 360° team will be headed up by head of PR Annaliese van den Berg.