Cooperate with Italian scoundrel (6)
I believe the answer is:
concur
'cooperate' is the definition.
(thesaurus)
'with italian scoundrel' is the wordplay.
'with italian' becomes 'con'.
'scoundrel' becomes 'cur' (I've seen this before).
'con'+'cur'='CONCUR'
(Other definitions for concur that I've seen before include "Stone pile" , "Give assent" , "Agree or happen together" , "run together" , "share the same opinion" .)