Local shares were down 9.98 points, or 0.32 per cent, to 3,137.35 by midday on Monday, amid a wider fall in Asian bourses.
Some 1.49 billion shares worth $346.4 million changed hands in the Singapore market.
There were 128 gainers, verus 185 losers.
"We've not had a fantastic start this year," said Mr Vasu Menon, the vice-president for wealth management research at OCBC Bank in an interview with Bloomberg TV.
"Asia is facing economic headwinds. China is trying to engineer an economic slowdown to ensure more sustainable economic growth. We're likely to see more volatility in the coming weeks as the U.S. earnings season gains pace."