The main stock index edged down 0.03 percent, or 2.02 points, to 6,449.66. It had closed at 6,463.06 on Friday, the highest since May 23, Reuters data showed.
Foreign investors accounted for around 52.2 percent of the day's turnover of 1.04 billion rupees ($8.22 million), in line with this year's daily average of 1.05 billion rupees.
The bourse saw a net foreign inflow of 439 million rupees, extending year-to-date inflows to 14.45 billion rupees.
The market's 14-day Relative Strength Index (RSI) was still in overbought territory, at 75.262 on Tuesday and has been above the upper neutral level of 70 since April 16, Thomson Reuters data showed.
"There'll be profit-taking till we see some positive news," said a stockbroker asking not to be named.
Shares in Commercial Bank of Ceylon gained 1.64 percent to 124 rupees, while conglomerate and market heavyweight John Keells Holdings fell 0.63 percent took 281.70 rupees.
The rupee ended weaker at 126.50/52 per dollar from Monday's close of 126.20/55 on importer demand for the greenback, dealers said.
($1 = 126.5000 Sri Lanka rupees)
(Reporting by Ranga Sirilal and Shihar Aneez; Editing by Subhranshu Sahu)