Rose Wangen-Jones has been made the head of account management and Peter Lovatt will take on the role of vice-chairman.
Both positions are designed to provide Saatchis' clients with a better level of service.
Wangen-Jones, who will remain as the account director on Comet, will be responsible for improving processes and systems for clients, while maintaining training and development of all agency managers.
Lovatt, previously Saatchis' director of professional services, will work to add value to clients' business by anticipating their needs and policing standards across all the agency's disciplines.
Both Wangen-Jones and Lovatt will report to Lee Daley, Saatchis' chairman and chief executive.
Daley said: "I have thought long and hard about the structure of our management team to guarantee brilliant day-to-day service and the delivery of excellent work. Rose and Peter are highly talented managers and will ensure we provide the greatest possible results for clients."