Will Orr, a senior executive at Mother, is returning to WCRS as its managing director.
Orr, who worked at WCRS five years ago, replaces Jeremy Bowles, who left the agency in April. Orr is the first hiring by Debbie Klein, the new chief executive of WCRS.
Orr has been brought in to run the agency on a day-to-day basis and he will also head up the 3 account. He will buy a stake in the agency, which was bought out by its senior management team last year.
Orr has been running Mother's Boots, Observer and SkyBet accounts for the past two years. Before that, he was Leagas Delaney's marketing director.
During his four years at WCRS he handled Orange.
He said: "WCRS has always had fantastic brand-building skills and people. Now, there's renewed energy too. I'd only leave Mother to be part of something as exciting as this."
Klein added: "Will has the benefit of having grown up here, yet he will bring with him a new perspective and new ways of working."
Klein has also made two promotions in the planning department. Cameron Saunders, who has been oversee-ing the department since last year, has been made the group strategy director. He will work on strategic approaches for the WCRS Group companies.
These include Personal, its direct arm, Meme, its digital division and Woo, its sales promotion operation.
Herve Hannequin has been promoted to head of planning. Hannequin has been at WCRS since 2004, working on Mini, Heinz and Danone. He has also worked at Brand Genetics, JWT Europe and Saatchi & Saatchi.
The management line-up is completed with the promotion of Simon Peck to deputy head of account management. Peck has been at WCRS for seven years, most recently as the group account director on BMW and 118 118.