** Shares of Star Entertainment SGR.AX rise as much as 11.9% to A$0.118, their highest level since Sept 17** Embattled casino operator names Bruce Mathieson Jr. as new CEO as he relinquishes position as chairman** Appoints U.S. gaming group Bally's BALY.N Chair Soo Kim as chairman** Shares post biggest intraday pct gain since Nov 21** 7.5 mln shares change hands, 1.1 times the 30-day average** YTD, shares down 44.7%
(Reporting by Nichiket Sunil in Bengaluru)
((Nichiket.Sunil@thomsonreuters.com))