** Shares of Chinese software service provider Vobile Group 3738.HK drop 19.9% to HK$3.34, on course for their biggest one-day decline since April 7

** Stock hit the lowest since May 16; top loser on the Hong Kong bourse

** Vobile plans to sell 138 million new shares to third-party investors in share placement, raising HK$522 mln ($66.60 mln) for developing artificial intelligence generated content related business, to repay borrowings, and for working capital

** The new shares will be issued at HK$3.78 apiece, a 9.4% discount to Monday's close of HK$4.17 each

** Hang Seng Tech Index .HSTECH slips 0.2% while Hang Seng Index .HSI gains 0.2%

** YTD, stock down 9.4%

($1 = 7.8379 Hong Kong dollars)

(Reporting by Donny Kwok)

((donny.kwok@thomsonreuters.com))