** Shares of St Barbara SBM.AX fall 5.4% to A$0.2175

** Stock fell as much as 6.5% to A$0.215, their largest intraday pct fall since Feb 28

** Gold miner revises FY25 production from its Simberi operation to 55,000 ounces-65,000 ounces vs earlier guidance 65,000 ounces-75,000 ounces

** Also hikes FY25 all-in-sustaining cost (ASIC) at Simberi to A$3,900-A$4,200/ounce vs A$3,200-A$3,600/ounce earlier

** Stock down 2.2% YTD, including current session's moves

(Reporting by Nikita Maria Jino in Bengaluru; Editing by Lincoln Feast.)

((Nikita.Jino@thomsonreuters.com;))