WordNet (r) 3.0 (2006):

collective bargaining
    n 1: negotiation between an employer and trade union

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "collective bargaining":
   bargaining, chaffer, chaffering, coming to terms, company union,
   craft union, dickering, haggle, haggling, higgling,
   horizontal union, industrial union, labor union, local,
   local union, negotiation, organized labor, package bargaining,
   pattern bargaining, trade guild, trade union, union local,
   vertical union