A French wine cartel broken up (6)
I believe the answer is:
claret
'a french wine' is the definition.
(I've seen this before)
'cartel broken up' is the wordplay.
'broken up' is an anagram indicator.
'cartel' anagrammed gives 'CLARET'.
(Other definitions for claret that I've seen before include "Deep purplish colour" , "French wine" , "Deep red colour" , "Dark purplish-red colour" , "Wine from the Bordeaux region" .)