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.
The Straits Times Index declined 0.49 percent or 17.4 points to end at 3,529. 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, posting its first weekly drop in six.
The city-state's top lenders Oversea-Chinese Banking Corp dropped 0.8 percent, United Overseas Bank lost 1 percent while DBS Group Holdings edged up 0.1 percent.
Active stocks included, Viking Offshore and Marine climbing 7 percent to S$0.01 while MarcoPolo Marine plunged 10 percent to S$0.05.
Singapore Post, which provides domestic and international postal services, climbed 7 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 0.2 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 3.9 billion shares worth S$1.9 billion changed hands, with losers outnumbering gainers 284 to 180.