RockCorps, based in Los Angeles, is sponsored by Orange in the UK and France.
Advertising for RockCorps in these markets was previously handled by Orange's incumbents Fallon and Poke in the UK and Publicis Conseil in France. RockCorps did not have a US incumbent.
Recent activity for RockCorps has included an interactive site, created by Poke, where users upload their voices and recreate songs from bands such as The Ting Tings and MGMT.
Stephen Greene, the chief executive and co-founder of RockCorps, said: "We love what 18 Feet & Rising is building, and its creative sensibility fits RockCorps perfectly. We are thrilled to be linking up to take this movement as far as we can together."
Orange RockCorps launched a national TV campaign by Fallon in 2009, called "stand up and be counted". The ad was set against a gradually regenerating urban backdrop in order to highlight how the volunteers helped transform their surroundings.