The benchmark Straits Times Index slumped for the eighth straight session on Monday, closing 4.44 points, or 0.14 per cent, down at 3,084.41.
A morning buying spree gave way to an afternoon selldown, resulting in a downbeat close.
Some 3.94 billion shares worth $1.42 billion changed hands. Losers outnumbered gainers 229 to 176 with 394 unchanged.
The gainers included Golden Agri-Resources, up four cents to 56.5 cents, while Noble Group was among the losers, sliding two cents to 81 cents.
Singapore's regional peers fared better, with Hong Kong up 0.65 per cent, Shanghai soaring 1.90 per cent and South Korea 0.95 per cent higher.
But Japan dipped 0.18 per cent.