Minnec's predecessor, Sez Maxted, will become Draft London's first chairman, with a remit to focus on new business and the strategic direction of the agency.
The move is designed to bolster the London management team, enabling the UK office to play a more prominent role in the network's international operations as its lead European agency.
Minnec joined Draft Chicago in 1996 following stints at Ogilvy & Mather, where he ran the Sears account, Grey Advertising and Leo Burnett. At Draft, he was responsible for the huge United States Postal Service account.
As the Draft network's director of global initiatives, he was responsible for applying best practice across the group's various outposts. He also ran Draft Chicago's new business team and has held international positions on several of the agency's worldwide accounts.
Minnec, who worked closely with Maxted last year on Draft London's successful pitch for the UK Post Office account, said: "London remains one of the great centres of our industry, and the growth of Draft here presents some fascinating challenges. Sez and I share similar ambitions for Draft London.
"Obviously, my experience in the US can immediately be brought to bear on the Post Office account, but this position will allow me to play a major role across our existing client base."
Launched in 1978, the Draft network had to wait until its 2002 merger with Lowe Live before it could boast a London office of any size.
Maxted, formerly the chief executive of Draft's Oxford office, was brought in to run London in February 2003.
In 2004, the agency enjoyed its most successful year under Maxted's stewardship, winning the consolidated Saab/Vauxhall account as well as the Post Office, Teacher Training Agency and Bombay Sapphire business.
Maxted said: "We want to ensure we play a wider role as Draft's lead European agency, so it was logical for me to alter my focus. We also wanted to bring in an absolutely first class managing director to strengthen our top team. John's credentials are second to none in this regard."
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