WordNet (r) 3.0 (2006):

contingent on
    adj 1: determined by conditions or circumstances that follow;
           "arms sales contingent on the approval of congress" [syn:
           contingent, contingent on(p), contingent upon(p),
           dependent on(p), dependant on(p), dependent
           upon(p), dependant upon(p), depending on(p)]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "contingent on":
   arising from, attributable to, based on, boxed in, caused by,
   circumscribed by, coming from, contingent, dependent, dependent on,
   depending, depending on, depending on circumstances,
   derivable from, due to, hedged about by, hinging on, incident to,
   incidental to, occasioned by, owing to, predicated on,
   resulting from, revolving on, subject to, turning on