Old Roman company employing decorator (6)
I believe the answer is:
cicero
'old roman' is the definition.
(Roman statesman)
'company employing decorator' is the wordplay.
'company' becomes 'co' (abbreviation).
'employing' is an insertion indicator.
'decorator' becomes 'icer' (some decorating a cake with icing).
'co' going around 'icer' is 'CICERO'.
(Other definitions for cicero that I've seen before include "Old politician" , "Philosopher" , "accomplished orator" , "Orator's" , "Statesman from Rome" .)