Pub profit to negotiate (7)
I believe the answer is:
bargain
'negotiate' is the definition.
(bargaining is a kind of negotiating)
'pub profit' is the wordplay.
'pub' becomes 'bar' (both are drinking establishments).
'profit' becomes 'gain' (synonyms).
'bar'+'gain'='BARGAIN'
'to' acts as a link.
(Other definitions for bargain that I've seen before include "Deal; cheap buy" , "Agreement, deal" , "Deal; item at low price" , "value for money" , "Thing bought cheaply" .)