73, down 0.96 percent (66.30 points) while the more liquid Milanka index fell 1.
17 percent (73.32 points) to close at 6,219.03, according to stock exchange figures.
Turnover was 1.6 billion rupees.
People's Merchant was the most actively traded stock, with over 3.3 million shares changing hands.
It closed at 22.80 rupees, up 1.40.
Asiri Hospital Holdings was also actively traded with 12 million shares done and closing at 11.70 rupees, up 3.40.
Brokers Lanka Securities said the healthcare sector emerged as the highest gainer of the day as investors bought into Asiri Hospitals and Asiri Surgical Hospitals which were among the top gainers.
Newly-listed tea exporter HVA Foods was also heavily traded with over 4.
3 million shares traded, and the top contributor to turnover, closing at 37.30 rupees, down 2.20, after hitting a high of 40.
50.
"The Colombo bourse lost steam today as investors decided to book profits whilst staying away from aggressive buying," SC Securities said in a report.
"A distinct reduction in retailer and high-net-worth participation coupled with fewer block trades contributed to the reduction in turnover for the day.
"
The sole crossing or off-market private deal was 241,000 shares of National Development Bank at 135 rupees each. The stock closed flat at 136 rupees.