However, foreign investors bought shares on a net basis for a 19th straight session. The bourse saw a net foreign inflow of 314 million rupees, extending year-to-date inflows to 14.76 billion rupees.
The main stock index fell 0.42 percent, or 26.82 points, to 6,422.84, the lowest close since May 17.
Foreign investors accounted for around 52.8 percent of the day's turnover of 818.3 million rupees ($6.47 million), less than this year's daily average of 1.04 billion rupees.
"Consolidation is continuing and the market is taking time for the next run. We expect the market to be at these levels before gaining," said a stockbroker asking not to be named.
He expects the market to rise with more foreign buying after a road show, which is being held in Dubai with the participation of top market and regulatory officials to attract foreign inflows into the bourse.
Shares in conglomerate John Keells Holdings fell 0.82 percent to 279.40 rupees, while Commercial Bank of Ceylon lost 0.56 percent to 123.30 rupees.
The market's 14-day Relative Strength Index (RSI) was still in overbought territory, at 72.992 on Wednesday and has been above the upper neutral level of 70 since April 16, Thomson Reuters data showed.
The rupee ended firmer at 126.43/45 per dollar from
Tuesday's close of 126.50/52 on thin volume of inflows from remittances and stocks-related transactions, dealers said.
($1 = 126.5000 Sri Lanka rupees)
(Reporting by Ranga Sirilal and Shihar Aneez; Editing by Subhranshu Sahu)