** Shares of Sihuan Pharmaceutical Holdings Group Ltd

soar 41.7% to HK$1.02, their highest levels since February 2023, and on course for a second session of gains

** Stock on course for the biggest one-day pct rise since January 2021, if gains hold

** Stock is top pct gainer in the Hang Seng Composite Index

and in healthcare index , which are up 1.9% and 1.4%, respectively

** Co said it will conduct on-market share repurchase of up to HK$500 mln ($64.37 mln), including HK$5.36 mln worth of shares repurchased by the company in the first half of 2014, and the share buyback will be funded by available cash reserves

** Hang Seng Commerce & Industry Index rises 2.3% and Hang Seng Index climbs 1.8%

** Stock up 50.8%, YTD

($1 = 7.7670 Hong Kong dollars)

(Reporting by Donny Kwok)

((donny.kwok@thomsonreuters.com))