The Colombo Stock Exchange's main index fell 0.81 percent, or 45.67 points, to 5,608.13, its lowest level since Sept. 11.

"There were margin calls by brokers and retail investors had to sell their shares to settle credit for their earlier transactions," a stockbroker said on condition of anonymity.

"Lack of positive news to boost sentiment is also a reason the market fell."

The market saw a net foreign inflow of 46 million rupees, extending the net offshore inflow to the tune of 33.29 billion rupees so far this year.

Turnover was 515.4 million rupees ($4.01 million), around half of this year's daily average of 949 million rupees.

The rupee closed firmer at 128.75/80 to the dollar compared with Monday's close of 128.90/129.10 on dollar sales by banks, dealers said.