Weber Shandwick won a six-way pitch for TouchLocal's business, and has been charged with both B2B and consumer work.
The agency's London office will target internet users with TouchLocal's 'Circles' social networking engine, allowing members to contact others in the area while recommending and reviewing businesses to each other.
Led by associate director Rebecca Grant, the Weber Shandwick team will also promote the site to businesses looking to advertise on the internet.
TouchLocal CEO Tamer Ozmen said his site will aim to bring 'practicality' to social networking, a medium he describes as currently 'lacking any real purpose'.
The business review site will expand into the US in the next few months thanks to capital backing from tech specialist Balderton Capital.