** Shares of Star Plus Legend Holdings 6683.HK plunge 20.1% to HK$7.18, their lowest point since July 9
** Stock on course for the biggest one-day pct drop since July 21
** Intellectual property creator and operator plans sale of 54.5 mln new shares to key shareholder Frank Lai, who is chief financial officer of the co in a share placement, raising HK$392 mln ($50.47 mln) for developing exclusive celebrity IP, among others
** The shares will be issued at HK$7.20 apiece, a 19.1% discount to Wednesday's close of HK$8.99 each
** Says Lai will subscribe for the new shares following sales of 75 mln existing shares at the same price to third party investors
** YTD, Star Plus shares up 50.2%, Hang Seng TECH Index .HSTECH up 31.8%
($1 = 7.7675 Hong Kong dollars)
(Reporting by Donny Kwok)
((donny.kwok@thomsonreuters.com))