Analysts said investors were cautious and waited for direction despite the central bank's policy easing as concerns over a weakening rupee and high lending rates dented sentiment.
The main share index closed 0.5 percent, or 30.34 points firmer at 6,151.79, its highest close since Aug. 2.
Nestle Lanka PLC, which produces and markets food and dairy products, rose 10.29 percent to 2,259.80 a day after Sri Lanka ordered immediate suspension of New Zealand milk powder imports and recalled products from the market.
Shares in Leading fixed line telephone operator Sri Lanka Telecom rose 2.30 percent to 40 rupees a share.
Turnover was 725 million rupees ($5.51 million), less than this year's daily average of about 928.7 million rupees.
Foreign investors were net buyers of 208.3 million rupees worth of shares, extending the net foreign inflow so far this year to 16.31 billion rupees.
($1 = 131.6000 Sri Lanka rupees)
(Reporting by Ranga Sirilal; Editing by Anupama Dwivedi)
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