** Shares of Great Boulder Resources GBR.AX fall as much as 5.4% to A$0.070, lowest since Sept. 18

** Mineral explorer says it will raise A$5 million ($3.29 million) via a placement at an issue price of 6.75 Australian cents per share

** Issue Price represents an 8.8% discount to stock's last close

** Stock posts its biggest intraday pct fall since Sept. 15

** GBR currently down 4%, bringing YTD gains to 72.1%

($1 = 1.5179 Australian dollars)

(Reporting by Adwitiya Srivastava in Bengaluru)

((Adwitiya.Srivastava@thomsonreuters.com))