Brokers find a convenience (6)
I believe the answer is:
agents
'brokers' is the definition.
('agent' can be a synonym of 'broker')
'a convenience' is the wordplay.
'convenience' becomes 'gents' (I've seen this before).
'a'+'gents'='AGENTS'
'find' is the link.
(Other definitions for agents that I've seen before include "They act for actors" , "Spies" , "Sales reps" , "Instruments" , "travelling salesmen" .)