Bolton, who had ran JWT for five years, was replaced as JWT CEO in November by Toby Hoare, who was brought in to restore the fortunes of the UK's second-largest advertising agency after it lost out on a string of major accounts including J Sainsbury and British Airways.
His appointment at Enterprise IG sees the consultancy's current chief executive, Dave Allen, head in the opposite direction. Allen will be based at JWT's offices where he will be chief executive of the global Vodafone account, dubbed Team Vodafone, which he had already been running on a part-time basis while at Enterprise IG.
"This is a fantastic new opportunity for me and I am looking forward to building on the legacy that Dave has created. The key priority will be to develop the company's culture in other markets outside of Europe and strengthen relationships with multinational business on a global and regional basis," Bolton said.
Bolton, who will be based in London, will begin his new role in late January and will be charged with maintaining Enterprise IG's leading market position and growing the business in North America and the burgeoning Asian region.
Mark Read, WPP's director of strategy, said: "Dave is one of the founding fathers of Enterprise IG. He built it from a series of acquisitions and moulded it into one company. He is passionate about working with clients and already has close ties with Vodafone which will make for a smooth transition to his new role.
"At Enterprise IG, I have every confidence that Simon will take the company to its next stage of development. He has the right blend of international experience and with his energy and drive he can motivate people to manage and win multinational clients' business."
Bolton's arrival follows Enterprise IG's recent appointment by Deloitte, alongside a team of other WPP agencies, to work across its marketing business, with Enterprise IG responsible for for branding and identity.
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