French, who will retain his base in Asia, will be available to all of WPP's operating companies on a consulting basis for group clients.
The appointment stems from WPP's ongoing aim to develop its parent role by providing further support for its agencies and their clients.
The marketing strategist, Peter Dart, and the new-business planner, Jon Steel, have also taken-up cross-group positions in their relevant sectors as part of this strategy.
French describes his new position as similar to that of a creative godfather. He said: "Your godfather is someone you go to with problems when you can't talk to your dad. He can advise and guide without too much of an eye on what is acceptable or correct. Everybody needs a godfather."
French began his advertising career in the UK, working as a copywriter for Holmes Knight Ritchie in the late 70s and early 80s, having left his own start-up agency, Blacker Hyde, in Birmingham.
In 1983, he relocated to Singapore as a creative director for O&M. After leaving to work for a spell at Batey Ads and the Ball Partnership, he rejoined O&M's network as a regional creative director.
Five years later, he became the worldwide creative director in Singapore. French has twice won Asia's Campaign of the Decade award for Chivas Regal and OX, a spoof beer created to demonstrate the power of press advertising for Singapore Press Holdings.
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