The main share index fell 0.25 percent, or 14.08 points, to 5,677.31, from its highest since Feb. 22.
'Retailers are getting out. We will see local investors getting out, attracted by the high interest rates. But foreigners keep accumulating fundamentally sound stocks,' said a stockbroker on condition if anonymity.
The central bank last Friday left policy rates unchanged for a third straight month, saying inflation was expected to ease and reach more favourable levels by the end of the year.
That in turn comes after yields on treasury bills reversed their falling trend for the first time in 13 weeks.
The day's turnover was 557.01 million rupees ($4.40 million), around half of this year's daily average of 1.07 billion rupees.
Foreign investors were net buyers of 45 million rupees, extending year-to-date foreign inflows to 2.78 billion rupees.
The rupee ended firmer at a near one-month closing high of 126.45/55 to the dollar compared with Friday's finish of 126.50/60. ($1 = 126.6750 Sri Lanka rupees)
(Reporting by Ranga Sirilal and Shihar Aneez; Editing by Ron Popeski)
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