WordNet (r) 3.0 (2006):

steering committee
    n 1: a committee to arrange the order of business for some
         larger (legislative) body

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "steering committee":
   board, board of directors, board of regents, board of trustees,
   cabinet, cadre, council, directorate, directory, executive arm,
   executive committee, executive hierarchy, governing board,
   governing body, infrastructure, interlocking directorate,
   management, the administration, the brass, the executive,
   the people upstairs, top brass