Singapore shares dropped as much as 0.7 percent to a two-week low on Friday, dragged by financials such as United Overseas Bank.
Asian shares declined, with Korean and Japanese benchmark indices falling more than 1 percent amid talks of policy tightening in Europe.
U.S. oil rose for a third straight session after a survey showed strong compliance with output cuts by OPEC and others including Russia, offsetting concerns about surging U.S. production.
MSCI's broadest index of Asia-Pacific shares outside Japan slipped 0.3 percent and away from a record high, Reuters data showed.
At 0525 GMT, the Straits Times Index declined 0.22 percent or 8 points to 3,539. It ended 0.37 percent higher on Thursday, taking the year-to-date gains to about 4 percent.
The index has shed 0.7 percent so far this week, heading for its first weekly drop in six.
The city-state's top lenders Oversea-Chinese Banking Corp dropped 0.1 percent, United Overseas Bank lost 0.7 percent while DBS Group Holdings edged up 0.4 percent.
Active stocks included, Viking Offshore climbing 14 percent to S$0.02 while QT Vascular gained 5.6 percent to S$0.02 in afternoon trades. Jardine Matheson Holdings rose as much as 2 percent.
Singapore Post, which provides domestic and international postal services, climbed 4 percent after it reported a 37.2 percent jump in third-quarter profit, driven by improved performance in the Postal, eCommerce and Property divisions.
Keppel Corp shares were up 1 percent. Several of former key executives of Keppel and its offshore and marine units have been arrested for their alleged involvement in the corruption scandal involving Keppel Offshore & Marine, The Straits Times reported on Friday.
About 2.4 billion shares worth S$1 billion changed hands, with losers outnumbering gainers 224 to 150.