The move sees One Green Bean London become a team of almost 20 PR, social and digital specialists, headed by managing director Matt Buchanan and global executive creative director Kat Thomas.
One Green Bean was set up in Australia in 2007, and Havas acquired a majority stake in the firm in 2011. The Australian agency then launched in the UK at the start of the year with founding client Costa Coffee.
Since its launch, the agency has won project work for Pernod Ricard Winemakers, The Body Shop and B&Q, as well as securing a place on the Samsung PR roster. Following the merger, clients will now also include Arla Foods, Chivas, Rimmel, Peperami and Reckitt Benckiser.
The merger only affects Havas PR London. Havas PR offices in Manchester and Edinburgh are unchanged.
Buchanan said: "We’ve been overwhelmed with the positive reaction from prospective clients since our launch in January, our offering built around a modern insight-led approach to PR and content has definitely resonated.
"The newly combined agency gives us even greater fire-power, and the opportunity to work with not only the existing Havas PR clients, but also up-weight the PR and social integration within Havas Worldwide London."
Daniel Floyed, managing partner of Havas Worldwide London added: "One Green Bean is a truly unique business – in terms of its people, its philosophy and its output. Given the changing demands of clients and their increased focus on owned and earned media, it’s the right time to up-weight our capability in the PR and social space by bringing together these two businesses under one strong brand."
In May, Havas merged its brand entertainment PR agency Cake with Havas Sports & Entertainment creating a UK outfit with a com ined turnover of £12m. The merged business, called Havas SE Cake, operates under Adrian Pettett, CEO and co-founder of Cake.