"The score indicates that these countries continue to have a serious corruption problem in their public sector."
In the south Asia region, except for Bhutan, with a score of 5.7, Sri Lanka's neighbouring countries have failed to record a significant increase, TI said.
India's score is 3.3 while Maldives at 2.3, Bangladesh at 2.4, Pakistan at 2.3 and Nepal at 2.2 continue to be below 3.0.
The Corruption Perceptions Index, now in its sixteenth year, ranks countries in terms of the degree to which businesspeople and country analysts perceive corruption to exist among public officials and politicians.
It draws on thirteen different expert assessments and business surveys from eleven independent institutions.
The vast majority of the 178 countries included in the 2010 index score below five on a scale from 0, perceived to be highly corrupt, to 10, seen as having low levels of corruption.
Commenting on this year's score, J C Weliamuna, Executive Director of Transparency I