Acts I deny working for cartel (9)
I believe the answer is:
syndicate
'cartel' is the definition.
(thesaurus)
'acts i deny working' is the wordplay.
'working' indicates an anagram.
'acts'+'i'+'deny'='actsideny'
'actsideny' with letters rearranged gives 'SYNDICATE'.
'for' acts as a link.
(Other definitions for syndicate that I've seen before include "Group of promoters with a common interest" , "Group working together to promote common interest" , "Organised group of individuals" , "Group working to a common aim" , "Publish simultaneously in a number of newspapers" .)