Arnold's UK offering, Arnold London, will launch with Volvo as a founding client. The global Volvo account is shared between Arnold US and Nitro, which says it will continue to handle the UK business.
Shearer, who is still contractually tied into Nitro as a shareholder, will continue to work on Nike for Nitro in a freelance capacity until his non-compete clause runs out.
The new agency is also understood to be close to appointing two further founding partners, a planning director and a new-business director.
Shearer and Fourie's departure follows that of Bruce Crouch, the former managing director of Nitro, who left in 2006 and recently launched the start-up Audacity.
LONDON - Arnold, the Havas-owned US agency, is opening a London shop, headed by Paul Shearer, the global executive creative director at Nitro, and Johan Fourie, its managing director.