** Meituan 3690.HK slips 9.7% to HK$105, lowest since August 28, 2024; set for biggest one-day pct drop since April 7

** Stock top pct loser on Hang Seng Tech Index .HSTECH and Hang Seng Commerce & Industry Index .HSNC

** China's leading food delivery group's Q2 adjusted net profit plunges 89%, hit by rising competition in the instant retail sector; Q2 revenue up 11.6%, but misses expectations

** Co warns that efforts to retain customer in competitive market will raise cost, squeeze profit margins in near-term

** Citi downgrades to "neutral" from "buy" on uncertainty over core local commerce's profitability

** Assigns "high-risk"; trims PT to HK$133 from HK$188

** Jefferies maintains "buy"; trims PT to HK$139 from HK$155 after Q2 revenue miss

** YTD, stock falls 30.3%

(Reporting by Donny Kwok)

((donny.kwok@thomsonreuters.com))