The main stock index ended 0.23 percent, or 16.48 points, weaker at 7,089.06, slipping from its highest close since Sept. 25 hit on Friday.
"The bourse opened the week on a negative note despite most counters gaining. This was due to dips on index-weighted counters," TKS securities said in a note to investors.
Foreign investors were net sellers of 60.99 million rupees ($431,940) worth of shares extending the year to date net forging outflow to 2.97 billion rupees.
"Foreign activity was fairly dormant with an outflow recorded for the day," TKS said.
Turnover was 641.1 million rupees, compared with this year's daily average of 1.12 billion.
Shares in conglomerate John Keells Holdings fell 1.06 percent, while Commercial Bank of Ceylon, the country's biggest listed lender, fell 0.50 percent.
(reuters.com)