Hong Kong shares finished Wednesday with more losses as world markets retreated ahead of the US Federal Reserve's latest policy decision that many expect to end with another big interest rate hike.

The Hang Seng Index tumbled 1.8 percent, or 336 points, to 18,444.

The Shanghai Composite Index eased 0.2 percent, or 5 points, to 3,117, while the Shenzhen Composite Index slipped 0.4 percent, or 7 points, to 2,004. (AFP)