The Collaborative International Dictionary of English v.0.48:

Talebearer \Tale"bear`er\ (t[=a]l"b[^a]r`[~e]r), n.
   One who officiously tells tales; one who impertinently or
   maliciously communicates intelligence, scandal, etc., and
   makes mischief.
   [1913 Webster]

         Spies and talebearers, encouraged by her father, did
         their best to inflame her resentment.    --Macaulay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

talebearer
    n 1: someone who gossips indiscreetly [syn: tattletale,
         tattler, taleteller, talebearer, telltale,
         blabbermouth]

Moby Thesaurus II by Grady Ward, 1.0:

43 Moby Thesaurus words for "talebearer":
   a tale-bearing animal, betrayer, blab, blabber, blabberer,
   blabbermouth, busybody, canary, delator, fink, gossip,
   gossip columnist, gossiper, gossipmonger, informer, narc, nark,
   newsmonger, newspaperman, peacher, quidnunc, rat, reporter,
   rumormonger, scandalmonger, sieve, sneak, snitch, snitcher, spy,
   squealer, stool pigeon, stoolie, tabby, taleteller, tattler,
   tattletale, telltale, tipster, tittle-tattler, troublemaker,
   whistle-blower, yenta