The Singapore stock market was 0.3 per cent weaker at 3,296.82 points in mid-morning trading.
Negative sentiment after a Malaysian Airlines plane was shot down over Ukraine weighed on trading.
Asian stocks also faltered, with the Hang Seng Index down 0.59 per cent. Japan's Nikkei was l.25 per cent lower. Malaysia's KLCI lost 0.37 per cent.
Malaysian Airlines shares sank 13.33 per cent to 0.195 ringgit, bringing the drop this year for the stock to around 37 per cent.
The shares recovered from an earlier low of 0.185 ringgit.