BUZZ-WuXi AppTec's HK shares drop most in 6 months on potential share sale
** Hong Kong shares of new drug researcher and developer WuXi AppTec Co Ltd 2359.HK slide 11.4% to HK$93.40, the biggest daily pct decline since Dec. 15, if losses hold
** Stock hits the lowest since June 6 and is down for a third straight session; it is also the biggest pct decliner on the Hang Seng Composite Index .HSCI
** Shanghai-listed shares WUXAY drop 10%
** Shanghai-based co says its biggest shareholder intends to sell up to 88.68 mln A shares, or 3% of the issued shares capital, through bidding and block trading nP8N2XU00C
** Says the sale will not lead to any change of control in the company
** Hang Seng Commerce & Industry Index .HSNC falls 2.9%, and healthcare index .HSCIH drops 3.7%
** Hang Seng Composite Index .HSCI drops 2.3% and the benchmark Hang Seng Index .HSI declines 2.5%
(Reporting by Donny Kwok)