The All Share Price Index closed at 4,237.16, down 0.33 percent (13.83 points) while the more liquid Milanka index fell 0.
08 percent (3.95 points) to close at 4,757.40.
Turnover was 1.2 billion rupees, according to stock exchange provisional figures.
"The sentiment is still retailer driven," said Nikita Tissera, manager - research at SC Securities.
"We still see upside potential for key stocks despite the drop in the overall indices. The lack of foreign activity however remains a slight concern."
Loss-making tableware exporter Dankotuwa Porcelain, which is in talks with a prospective investor seeking capital needed for a turnaround, was the most actively traded stock.
The stock closed at 18.50 rupees, up 1.50 with over 2.8 million shares traded.
Renuka Agrifoods was also heavily traded, closing at 4.
10 rupees, down 10 cents.
Piramal Glass Ceylon, whose Indian parent firm is reportedly seeking to exit glass manufacturing, closed at 2.
70 rupees, up 10 cents.
John Keells Holdings closed at 183.
75, up 3.75, while its subsidiary John Keells Hotels closed flat at 19.25.