Singapore shares edged up in morning trading on Thursday after United States Federal Reserve chairman Ben Bernanke's overnight comments that the central bank's asset purchases are not on a preset course.

The benchmark Straits Times Index gained 16 points, or 0.5 per cent, to 3,224.3 as at 12.45 pm.

A total of 1.9 billion shares worth $431.5 million changed hands by midday.

Gainers outweighed losers 164 to 140, with 659 counters unchanged.