The main share index rose 0.65 percent or 36.59 points at 5,663.36, after hitting its lowest since Dec. 28.
Foreign investors were net sellers of 248.5 million rupees ($1.95 million) worth of shares, but they have been net buyers of 352.6 million rupees so far this year.
Yields in Treasury bills rose on Wednesday for the first time in 13 weeks.
'It's not a healthy sign for the market. The market may reflect this from tomorrow,' a stockbroker said.
The rise in yield comes after the International Monetary Fund last month cautioned Sri Lanka over inflationary risks.
The market has fallen 3.2 percent since the IMF on Feb. 13 said Sri Lanka was facing slow growth, high inflation and lower tax revenue risks.
The day's turnover was 1.31 billion rupees, higher than the daily average of 1.05 billion rupees this year.
The rupee ended firmer at 127.25/30 to the dollar from Tuesday's close of 127.42/48 on exporter dollar sales, dealers said.
($1 = 127.5000 Sri Lanka rupees)
(Reporting by Ranga Sirilal and Shihar Aneez; Editing by Michael Urquhart)
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