E3's new offices will be based near Oxford Circus, enabling the agency to better serce its London-based clients as well as to "make its presence better felt on the tender circuit".
The agency is currently going through a recruitment process for a senior director to help oversee the London operation. It is also on the hunt for 12 staff, including designers, producers and account handlers to support existing and prospective business.
Bristol-based staff will also work from the London office on pitches and projects for existing clients.
Mike Bennett, E3 joint managing director, said: "We are rapidly moving towards achieving our goal of becoming a full-service agency.
"Business is buoyant and we have been successfully adding a raft of new services to our portfolio. We want to capitalise on this success. By establishing an office in London, we will offer closer contact with clients that insist on a presence in the capital."
E3's recent new-business wins include the Environment Agency and the V&A. It is also working on a project for Toni & Guy to build the hairdressing brand's first e-commerce site.
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