Muir will take responsibility for group new business across O&M, OgilvyOne, Ogilvy Interactive and Ogilvy PR. He will also co-ordinate the group's acquisition policy.
Muir said: "I am very lucky to have spent nearly ten years at Ogilvy. As such I have a strong sense across the group of the tremendous assets we have. My job is to make sure that these assets work together effectively for our clients.
I will over the coming weeks cease my role on futureOgilvy and transfer the knowledge and expertise built up into Ogilvy Interactive, allowing me to focus on this new role."
Ogilvy Interactive will offer clients digital and wireless capability and futureOgilvy, the group's dedicated digital and wireless business centre, will be closed.
The news comes after last month's appointment of Mark Earls, the executive planning director at Ogilvy & Mather, to the role of group planning director.