Hong Kong shares ended the morning sharply lower on Monday as investors wind down their expectations for a big Federal Reserve interest rate cut at the end of the month.
The Hang Seng Index slipped 0.8 percent, or 222 points, to 28,542 by the break.
Most Asian markets also fell in early trade, but all the firms on a new tech-focused board in China rallied on its opening day.
Oil prices extended last week's gains after Iran seized a British tanker in the Gulf, fuelling fresh concerns about supplies and a possible conflict in the tinderbox Middle East.
Traders took a step back after last week's gains as the New York Federal Reserve tempered comments from its president John Williams who had suggested the central bank would cut borrowing costs by 50 basis points at its policy meeting this month.
Bets that the Fed will only reduce rates by 25 points provided support to the dollar against most high-yielding, riskier currencies.
Shanghai fell 0.7 percent, with investors in China piling cash into companies listed on the country's new Nasdaq-style board.
Twenty-five stocks debuted on the Shanghai Stock Exchange's Sci-Tech Innovation Board – dubbed the STAR Market – in which listing and trading rules have been eased to help channel funding to start-ups.
Anji Microelectronics Technology (Shanghai) Co. was one of the stand-out performers, soaring more than 300 percent
There will be no limits on price movements for the first five days of trading, after which a daily 20 percent band is imposed. China's main exchanges are subject to a 10 percent band to contain volatility.
Singapore, Manila and Jakarta were also lower, though Wellington and Taipei edged up while Sydney and Seoul were flat. (AFP)