Market volume was 785 million shares valued at 745 million Singapore dollars (441 million US), down from 848 million shares worth 703 million dollars on Tuesday.
Gainers beat losers 247 to 237 with 1,040 stocks unchanged.
"Foreign houses are negative on SingTel because they don't think it's going to report good earnings tomorrow," a dealer from a local brokerage firm said.
Bearish sentiment also hit CapitaLand, which along with SingTel will report its earnings on Friday, as investors took a wait-and-see mode, the dealer said.
SingTel fell five cents to 2.40 on expectations earnings for the fiscal second quarter to September will slump from a year ago.
Analysts are predicting a net profit ranging between 707 million dollars and 744 million dollars - smaller than the 766 million dollars SingTel earned the year before.
The earnings drop is likely to be due to a slump in contributions from wholly-owned Australian subsidiary Optus.
Among other blue chips, Singapore Press Holdings dipped two cents to 4.44, Singapore Airlines dropped 10 cents to 11.40, while ST Engineering jumped four cents to 2.58.
CapitaLand gave up four cents to 3.36 on profit taking after six consecutive sessions of gains. City Developments added five cents to 8.75 while Keppel Land was flat at 3.92.
Banking stocks were mostly firmer with DBS adding 20 cents to 16.00 and Oversea-Chinese Banking Corp up 15 cents to 6.45, while United Overseas Bank tumbled 10 cents to 14.10.
Venture Corp retreated 20 cents to 12.60 on expectations its earnings may not improve until next year, dealers said.
Other technology stocks were flat to higher with Creative Technology steady at 12.70, Chartered Semiconductor up five cents at 1.14 and STATs ChipPAC up 1.5 cents to 99.5 cents.