Singapore shares slipped on Friday as investors were still troubled by recent worries, such as the possible United States-led attack on Syria and global economic weakness.

The benchmark Straits Times Index (STI) slid 9.09 points, or 0.30 per cent, to 3,028.94. Some 2.65 billion shares worth $1.65 billion switched hands.

This was the bellwether indicator's 11th slump in the last 12 sessions, bringing it down a total of 6 per cent for the month of August.

It was the index's worst monthly display since May last year, when it slid 7 per cent.

Regional markets ended mixed, with Hong Kong adding 0.12 per cent and South Korea gaining 0.99 per cent, but Japan dipping 0.53 per cent due to downbeat manufacturing numbers.

Here, the 30 STI component stocks also closed mixed, with 16 gainers, 13 losers and one unchanged.

Thai Beverage endured another rollercoaster ride, slumping 4.5 cents yesterday to 47.5 cents after charging up 10 cents on Thursday.

Olam International was in the spotlight, after unveiling a 48 per cent plunge in quarterly net profit on Thursday due to higher tax charges and challenging market conditions. It closed 2.5 cents down at $1.435.

In contrast, ComfortDelgro soared 6.5 cents to $1.845 after OCBC Investment Research upgraded it to "buy" with a $1.95 target price.