** Shares of Brightstar Resources BTR.AX fall as much as 24.6% to A$0.475, their lowest level since December 11
** Gold miner receives firm commitments to raise A$175 million ($121.94 million) via placement
** Issue price of A$0.50 per share represents a discount of 20.6% to stock's last close
** Co says funds raised will be used to provide equity component for development and construction of Goldfields Hub Project, others
** About 12.9 million shares change hands, 1.8x the 30-day average
** Stock up 27.3% this year, as of last close
($1 = 1.4351 Australian dollars)
(Reporting by Sherin Sunny in Bengaluru)
((Sherin.Sunny@thomsonreuters.com))