Publicis Worldwide's decision to bring Modem Media and Publicis Dialog into a global digital arm called Publicis Modem has led to sweeping changes within the group.
The move will see the Dialog name disappear, as it is subsumed into Publicis Modem. Martin Reidy, the former president of Modem, will take over as the chief executive of the combined offering, which will sit in Publicis' 82 Baker Street offices.
The decision has also led to the resignation of the Dialog global chief executive, Colin Hearn, who opposed the changes.
Maurice Levy, the chairman of the Publicis Groupe, said: "We have to expand day after day in everything we do. You can't expect everything to stay the same as we begin to offer clients more. It's obvious we'll have to make changes within the group to remain stable."
Levy's long-term plan for Publicis Modem is for the global digital arm to be responsible for 25 per cent of the group's entire revenue.
Levy said: "The world is changing like a tsunami, and everything is happening beneath our feet, and we don't see it. However, we will see it emerge brutally in the next couple of years.
"Nobody but us is preparing for this change on this scale. This is what our clients are telling us they want."
The move also includes the rebranding of the digital shop Modem London as Digitas London, which will spell further changes for the network.
The agency will now be responsible for spearheading Publicis Modem's digital strategy across Europe.
Norm Johnston, the former Modem managing director for Europe, has become the president of Digitas. His new role will see him opening offices across the continent under the new name.