** Shares of Regis Resource RRL.AX fall as much as 6.5% to A$4.180, their lowest level since May 13
** Stock logs biggest pct loss since July 9
** Gold explorer posts qtrly gold production of 87.4koz down from 106.4 koz pcp
** Says gold sales in June quarter drop to 96.8koz from 114.5koz last year
** Forecasts gold production of 350koz-380koz for FY26, largely flat compared to FY25 production of 373koz
** Separately, co agrees to acquire mining licence for the Southern Star gold prospect from Great Southern Mining GSN.AX for A$9 mln ($5.85 mln)
** GSN shares slip 3.7%
** YTD, Regis Resources stock up 69%, including the day's move
($1 = 1.5380 Australian dollars)
(Reporting by Ananya Verma in Bengaluru)
((ananya.verma@thomsonreuters.com;))