The 64-strong agency aims to double in size and fees by 2012, according to CEO Sacha Deshmukh.
To achieve this aim, it is appointing four MDs to lead each of the agency's major practice areas.
Brooke Clarke, MD of GCI's London office, will join the agency in January as MD of the corporate practice.
Mandate recently hired Rachael Sansom, previously European comms director at Motorola, as consumer MD and is conducting final interviews for a public affairs MD. Finally, Mike Birtwistle has been promoted to MD of the health practice. Nobody is leaving.
Deshmukh said: 'PR players who have got the strongest teams are going to grow during this recession. We are looking to build up Mandate to be double in size - in fees, market profile and headcount - by 2012.'
Mandate launched last year after the merger of AS Biss & Co and Republic PR.