The agency’s nine permanent staff will move into Karma’s offices in Farringdon, London, on Monday.
Grape’s managing director and founder, Mark Malone, will become the group’s head of social, while Joe Holt will remain in his position as the creative director. Both become shareholders in Karma.
Grape, which was founded in 2009, has worked with clients including Live Nation, Agent Provocateur, Fiat, Tesco and Samsung. It will be renamed and could be folded into Karmarama or Karma’s PR agency, Kaper, with which it has worked on joint pitches and clients for the past three months.
Ben Bilboul, the chief executive of Karma, said: "Mark and Joe share our ambition to significantly raise the quality of work in this space. We’ll be putting them right at the heart of our business."
Charles Watson, the group chairman of Karma, said he expected to grow the social division: "As Grape has its own portfolio of clients, I think it’s highly probable that we will be looking to hire more people in that area."