Central Bank profits have also contributed to high non-tax revenues from late last year.
Current expenditure increased at a slower 5.5 percent to 463.1 billion rupees, while capital expenditure slowed 5.8 percent to 113.7 billion rupees allowing budget deficit including grant financing to fall 18 percent to 221.4 billion rupees.
Compared to an estimated gross domestic product of about 5,500 billion in 2010, the deficit was 4.03 percent of GDP down from 5.59 percent a year earlier.
The deficit without granting funding was 3.9 percent of GDP for the six months (215.3 billion rupees) down from 5.28 percent of GDP (254.8 billion rupees) a year earlier.
In 2009 Sri Lanka ran a budget deficit of 10.3 percent of GDP with grant funding and 9.9 percent without grant funding.
Meanwhile