** Shares of Northern Star Resources NST.AX fall 4.9% to A$19.86, their lowest since April 9

** Gold miner reports quarterly gold sales of 385koz vs 401koz in the same quarter last year

** Co revises FY25 production and cost guidance to 1,630-1,660 koz at A$2,100-A$2,200/oz from 1,650-1,800 koz at A$1,850-A$2,100/oz

** Stock up 28.1% YTD, including session's moves

(Reporting by Jasmeen Ara Shaikh in Bengaluru)

((JasmeenAraIslam.Shaikh@thomsonreuters.com))