WordNet (r) 3.0 (2006):

wholesaler
    n 1: someone who buys large quantities of goods and resells to
         merchants rather than to the ultimate customers [syn:
         jobber, middleman, wholesaler]

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "wholesaler":
   agent, broker, chandler, connection, dealer, distributor,
   go-between, importer, intermediary, intermedium, jobber, liaison,
   link, marketer, mediary, mediator, medium, merchandiser, merchant,
   middleman, monger, regrater, retail dealer, retail merchant,
   retailer, shopkeeper, storekeeper, tie, trader, tradesman,
   tradeswoman, trafficker