Publisher entertained by very French companies (7)
I believe the answer is:
troupes
'companies' is the definition.
('troupe' can be a synonym of 'company')
'publisher entertained by very french' is the wordplay.
'publisher' becomes 'oup' (abbreviation for Oxford University Press).
'entertained by' indicates putting letters inside (I've seen this in other clues).
'very french' becomes 'tres' ('very' translated into French).
'oup' placed inside 'tres' is 'TROUPES'.
(Other definitions for troupes that I've seen before include "The acrobatic ones" , "performers of Swan Lake" , "Groups of entertainers" .)