The main stock index ended down 0.24 percent, or 14.43 points, at 5,953.19, retreating from a seven-month closing high in the previous session.
Shares have been rising on hopes of a fall in interest rates after Treasury Secretary P.B. Jayasundera and the central bank said official interest rates could ease in May and June.
The market has risen 3.3 percent through Monday since the treasury secretary's comments on official interest rates on April 9.
'We saw some profit-taking on retail counters at the end of the month, which brought the market down,' said a stock broker.
The turnover was 875.97 million rupees ($6.91 million), lower than this year's daily average of 965 million rupees.
Foreign investors were net buyers of 85.8 million rupees of shares, extending the net foreign inflow so far this year to 8.78 billion rupees ($69.27 million). Last year, the bourse saw a net inflow of $303 million.
The rupee ended a tad firmer at 126.70/75 per dollar from Monday's close of 126.65/85 on exporter dollar sales, currency dealers said. ($1 = 126.7500 Sri Lanka rupees)
(Reporting by Ranga Sirilal and Shihar Aneez; Editing by Jijo Jacob)
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