Worries of an United States-led attack on Syria sent Singapore shares sliding to a fresh nine-month low on Wednesday amid a regional selldown.

The benchmark Straits Times Index eventually closed down 29.84 points, or 0.98 per cent, at 3,004.18.

The bellwether indicator barely kept its head above the key 3,000-point mark at the close, having sunk to as low as 2,990.68 during the day.

Some 3 billion shares worth $1.45 billion changed hands.

The Singapore bourse joined its regional peers in a sea of red, with Hong Kong sinking 1.60 per cent, Japan down 1.51 per cent and Australia dropping 1.05 per cent.

Nearly all 30 STI component stocks finished in negative territory, with a mere three ending higher.

The three were ST Engineering, up three cents to $3.88, Wilmar International, two cents higher at $3.12, and StarHub, a cent in front at $4.13.