Business company (4)
I believe the answer is:
firm
I believe this clue is a double definition.
'business' is the first definition.
(firm is a kind of business)
'company' is the second definition.
(firm can mean a company or business)
(Other definitions for firm that I've seen before include "Steady commercial organisation?" , "Fixed" , "Hard" , "Unyielding; company" , "Unyielding business concern?" .)