In Europe and the Asia-Pacific region Stephan Beringer, the international president of Digitas has assumed a permanent operations role for both agencies.
Razorfish Europe president Darin Brown has moved to the position of Razorfish president of global accounts and innovation, while Razorfish Asia Pacific president Lee Sherman remains in his role.
Beringer will be focusing on pooling the two agencies' investment in offices, technology, non-proprietary data feeds, research and development.
In Latin America, similar efforts will be led by Razorfish Americas president Dave Friedman.
Finance and talent will be centralised and led by Digitas CFO Joe Tomasulo and Razorfish head of human resources Alicia Shankland respectively.
It is unclear whether there have been any job losses as a result of the changes, which follow the October acquisition of Razorfish from Microsoft in a deal valued at in excess of $500m (£300m).
Publicis Groupe has also moved to further align the two agencies with its cross-functional digital network VivaKi and its innovations unit Denuo.
Denuo will now report to Digitas worldwide chief executive Laura Lang.
Rishad Tobaccowala is relinquishing his day-to-day operational role as chief executive of Denuo to take on a broader role helping VivaKi and its clients into the future landscape.
David Kenny, managing partner of VivaKi, said: "The harmonisation principle has been simple. We do need two digital agencies. We don't need a redundant support framework, and we can simultaneously make each agency more agile and effective while protecting client confidentiality."