in league

in league
    adj 1: (usually followed by `with') united in effort as if in a
           league; "they found out that some policemen were in
           league with the criminals"
    

27 Moby Thesaurus words for "in league":
      affiliate, affiliated, allied, associate, associated, cabalistic,
      confederate, confederated, conspiratorial, corporate, coupled,
      enleagued, federate, federated, in cahoots, in collaboration,
      in collusion, in cooperation, in partnership, in with, leagued,
      married, paired, partners with, teamed, wed, wedded