The S&P SL20 closed 18.11 points higher at 3,229.00, up 0.56 percent.
Turnover was 1.31 million rupees, provisional data showed, up from 1.28 billion the previous day, with shares of 122 firms gaining against 63 losing.
Foreigners bought shares worth 486.36 million rupees, up from 439.08 million rupees the previous day, and sold 403.12 million rupees worth of shares, up from 49.25 million rupees.
Troubled Touchwood closed 1.10 rupees higher at 4.20 rupees with more than 24.4 million shares changing hands.
JKH closed 4.00 rupees higher at 223.00 rupees and featured in six crossings and Dialog closed 20 cents higher at 8.70 rupees and featured in one crossing.
Sri Lanka Telecom closed 80 cents higher at 39.50 rupees.
Asian Hotels and Properties closed 1.10 rupees higher at 70.00 rupees and Hemas Holdings closed 1.40 rupees higher at 33.00 rupees.
CTC closed 9.00 rupees lower at 1,036.00 rupees and AIA Insurance Lanka closed 26.00 rupees lower at 279.00 rupees.
Aitken Spence closed 1.80 rupees lower at 113.30 rupees and Singer Sri Lanka closed 5.80 rupees lower at 93.20 rupees.
Commercial Leasing and Finance closed 10 cents lower at 3.90 rupees and Sampath Bank closed one rupee lower at 171.00 rupees.
Troubled CIFL closed 10 cents higher at 1.20 rupees with more than 1.55 million shares changing hands.
The rupee strengthened to 131.46/47 against the US dollar in the spot market in late trading from yesterday's close of 131.55/60 on export conversions and foreign bank dollar sales amidst subdued importer demand, dealers said.
In gilt markets a liquid five year Treasury bond was trading at 11.68/72 percent, from an opening at 11.67/81 percent.