Stocks turned lower in Hong Kong on Wednesday as investors took a step back ahead of the Federal Reserve's latest policy decision and post-meeting statement, which they hope will provide clues about the bank's next moves.

The Hang Seng Index retreated 0.44 percent, or 119.05 points, to 26,667.71.

The benchmark Shanghai Composite Index lost 0.50 percent, or 14.86 points, to 2,939.32, while the Shenzhen Composite Index, which tracks stocks on China's second exchange, dropped 0.86 percent, or 14.06 points, to 1,628.62.