Morris, who has worked at Carat since joining as a graduate in 1994, will retain his current responsibilities as the head of planning but will also work closely with De Groose to ensure that the agency is delivering value to all clients.
In addition, De Groose, who was appointed the Carat managing director last September, has promoted the group business director, Richard Sexton, to the head of Carat's client services. The group business directors, Matthew Landeman, Steve Pople and Dino Ioannou, will now report to Sexton, who will retain his own business group.
Meanwhile, Jo Sutherland, another of Carat's group business directors, has moved across to the Aegis Media sister agency Vizeum to become its head of client management.
Morris said: "The new media landscape means we have to think differently about our business and ensuring that Carat has the right product to support our clients in this new environment is a task I'm relishing."
De Groose said: "Richard has played a key role in the growth of Carat, helping to redefine how media can drive value for our clients.
"He has an important part to play in helping us achieve our ambitions in 2011 and beyond."