Mother, which has offices in London, New York and Buenos Aires, has tasked Mr. Wall with leading the network, expanding into more markets, and driving the agency into new sectors, as the group looks to broaden its offering.
In London, where the agency was founded 18 years ago, Mother has been doing some exceptional work for existing clients -- particularly Ikea "Beds" and MoneySupermarket "Epic Strut" -- but new business and expansion have not been so dynamic.
The New York shop, which opened in 2003 and was Creativity Agency of the Year in 2009, has been relatively quiet recently, and the Buenos Aires office, launched in 2005, has remained small. Mother is known as Madre in Argentina, where Carlos Bayala and his wife Gabriela, who had both worked for Mother in London earlier, did a startup in 2006 when the pair decided to return to their native Buenos Aires. In 2013, Mr. Bayala was named a global creative partner at Mother, and returned to London.
Mother founder Stef Calcraft has sold his 25% shareholding back to the company and left, and Dylan Williams, partner and chief strategy officer, went to Publicis. Those departures left a gap in senior management and prompted the agency to seek its first global CEO.
Mother founder Robert Saville said in a statement, "Mother has needed Michael's skills in business leadership for a while. But more importantly we welcome a genuinely good person with the same passion for the transformative power of creativity into the family. I suspect Michael will make us all better."
In 1998, Mr. Wall became one of five founding partners of Fallon London, along with Robert Senior -- now worldwide CEO of Saatchi & Saatchi – working on campaigns including Sony Bravia "Balls," and Cadbury's "Gorilla."
Mr. Wall said in a statement, "Mother is a special company. I'm delighted to take on this role. Our shared ambition is to make sure Mother continues to lead the creative frontline as we accelerate our growth and impact in the markets we are already in, as well as those that we are eyeing up. And have some fun along the way."
Mr. Wall -- a Brit -- will be based in London and will become an equity partner in Mother along with Robert Saville, Mark Waites, Andy Medd and Matt Clark.
Mullen's CEO, Alex Leikikh, was made worldwide CEO of the U.S.-based Mullen Lowe Group at the time of the merger, leaving no clear role for Mr. Wall at the agency. He had been at Lowe and Partners since 2009.
Mr. Saville added, "We have been chasing Mr. Wall for years. He's not an easy man to catch. And he wasn't an easy man to beat either as Mother and Fallon faced up against each other over the years."
Mother London's billings were $247 million in 2014, down 5.2% from $261 million in 2013 (Nielsen).