Baidu's Hong Kong shares face worst day in 4 weeks on revenue miss

** Hong Kong shares of Chinese search engine giant Baidu BIDU slip 3% to HK$84.6 - on course for their biggest one-day pct drop since July 24, if current losses hold

** Stock hits the lowest level since August 12 on a second session of decline; top pct loser on the Hang Seng Tech Index HHSTECH and Hang Seng Commerce & Industry Index HHSCI

** U.S.-listed stock BIDU fell 2.6% on Wednesday

** Baidu fell short of market estimates for quarterly revenue, signalling persistent weakness in the advertising market amid prolonged economic uncertainty

** Co reported total revenue of 32.71 bln yuan ($4.56 bln) for the second quarter, compared with analysts' average estimate of 32.76 bln yuan

** YTD, Hong Kong stock up 3.2%, U.S. stock up 2.9%