The main index ended down 0.45 percent, or 26.95 points, at 5,927.41, its lowest close since Oct. 29.
Dealers said the market would not see a sustained gaining trend unless retail investors return to the bourse. The market has lost 0.42 percent since the central bank cut its key policy rates by 50 basis points on Oct. 15.
Shares in Asian Hotels and Properties fell 5.63 percent to 70.30 rupees.
The day's turnover slumped to 419.3 million rupees ($3.20 million), the lowest since Oct. 14 and less than half of this year's daily average of about 868 million rupees.
Foreign investors were net buyers of 10.2 million rupees worth of shares, extending the net buying so far this year to 23.27 billion rupees.
($1 = 131.0250 Sri Lanka rupees)
(Reporting by Shihar Aneez; Editing by Subhranshu Sahu)
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