McGarahan worked as a consultant for Equitable after its near-collapse in 2000 and subsequent investigations into its business practices.
He has taken a director role within CDR's 60-strong financial division, reporting to financial practice MD Patrick Donovan.
A comms director for a number of firms during his 20-year career, including Taylor Woodrow and Mecca Leisure, McGarahan has spent the summer out of the industry.
During the early 1990s he was board director at Paragon Communications.