** Shares of Brazilian payments firm StoneCo STNE.O jump 12.2% to $10.41 in afternoon trading

** STNE, on Thursday, authorized a share repurchase program of up to 2 billion reais ($343.9 mln), which does not have fixed expiration date

** Repurchases may be made from time to time through open market transactions, block trades, and privately negotiated transactions

** As of last close, STNE down 48.6% YTD

($1 = 5.8156 reais)

(Reporting by Arasu Kannagi Basil in Bengaluru)

((ArasuKannagi.Basil@thomsonreuters.com;))