** Shares of Unico Silver fall 11.3% to A$0.275, set for worst session since Aug. 5 - if current losses hold
** Silver explorer receives firm commitments to raise A$22.5 mln ($14.93 mln) via placement
** Issue price of A$0.27 per share represents a 12.9% discount to stock's last close
** Co says funds will be used to accelerate exploration at its Cerro Leon and Joaquin projects in Argentina
** Stock hits lowest level since Oct. 18
** USL has more than doubled in value so far this year
($1 = 1.5069 Australian dollars)
(Reporting by Nikita Maria Jino in Bengaluru)
((Nikita.Jino@thomsonreuters.com;))