** Shares of Mesoblast rise as much as 4.4% to A$1.1750, their highest levels since July 25

** The biotechnology firm enters into a convertible note subscription agreement to raise $50 mln with its largest shareholder Gregory George

** Says issue price of A$1.32 per share is at a ~17% premium, as of co's last trading price on Sept 27

** MSB stock up 270.9% YTD, including current session's moves

(Reporting by Kumar Tanishk in Bengaluru)

((Tanishk.Kumar@thomsonreuters.com;))