** Shares of Sichuan Kelun-Biotech Biopharmaceutical 6990.HK fall 6.4% to HK$336, on course for the biggest one-day drop since May 7

** Stock on track to snap two straight sessions of gains

** The oncology-focused drug developer plans sale of 5.92 mln new shares, or 2.5% of the enlarged share capital, in share placement raising HK$1.96 bln ($249.8 mln) for R&D, products commercialization and expanding product pipeline portfolio

** The new shares will be issued at HK$331.8 apiece, or 7.6% discount to Wednesday's close of HK$359 each

** Hang Seng Biotech Index .HSHKBIO slips 0.7%, while Hang Seng Index .HSI climbs 0.7%

** YTD, stock up 107.6%

($1 = 7.8452 Hong Kong dollars)

(Reporting by Donny Kwok)

((donny.kwok@thomsonreuters.com))