The Hang Seng index closed 0.2pc lower at 26,042.69 points, paring some losses after hitting its lowest level since Sept. 4 in early trade.
The Hang Seng China Enterprises index also fell 0.2pc.
Energy shares dipped 0.5pc, the IT sector lost 0.7pc, the financial sector fell 0.3pc and the property sector rose 0.9pc.
Fears of a U.S. economic slowdown grew after the Institute for Supply Management's (ISM) index of factory activity, one of the most closely watched data on U.S. manufacturing, dropped 1.3 points to 47.8, the lowest level since June 2009.
The S&P 500 index touched four-week lows overnight. In Asia, MSCI's Asia ex-Japan stock index fell by 0.8pc, while Japan's Nikkei index closed down 0.5pc.
China's financial markets are closed for the week for the National Day holiday.
"With A-shares closed, the U.S. stock market's movement is the main point of reference for the Hang Seng Index," analysts at CHIEF Group wrote in a note on Wednesday, adding that U.S. economic data due this week, such as private sector jobs figures, may also sway the Hong Kong market.
In Hong Kong, police shot the first protester with live ammunition in almost four months of unrest on Tuesday, in some of the most widespread violence since the disruptions erupted in early June.
Hong Kong will report August retail sales shortly after the stock market closes.
Citi's analysts said in a note on Wednesday the numbers may "decline very sharply" amid the protracted protests, global trade tensions and yuan depreciation, which hurt mainland Chinese tourists' spending power.
About 1.2 billion Hang Seng index shares were traded. The volume traded in the previous trading session was 1.34 billion.