Against the backdrop of attack over corruption issue, Prime Minister Manmohan Singh today said "big ticket" graft involving commercial entities would be addressed through changes in the law while ensuring protection to honest public servants in a better way.

Asserting that the government would do everything to ensure probity, transparency and accountability in the work of public authorities, he cautioned that creation of "mindless atmosphere of negativity and pessimism" over corruption could hurt the country's image and morale of the Executive.

Addressing 19th annual conference of CBI and state anti-corruption units here, Singh said "newer modi operandi" are being adopted for corrupt activities as faster economic growth over the last two decades has "led to newer opportunities for corruption, ones associated with the specialisation and expansion of an economy".

He said amendments are being considered to the Prevention of Corruption Act, not only in view of the judicial rulings on its provisions, "but also with the purpose of filling certain gaps" in the legislation and bringing in line with international practices.

"Experience has shown that in vast majority of cases, it is difficult to tackle consensual bribery and the supplier of the bribe goes scot free by taking resort to provisions of the Act... Experience has also shown that big ticket corruption is mostly related to operations by commercial entities," he said, adding these would be taken care of in the proposed changes in the law.

"It is proposed to include corporate failure to prevent bribery as a new offence on the supply side," Singh said.

At the same time, he said the government is also examining how the Prevention of Corruption Act can be amended to protect honest public servants more effectively.

His comments came at a time when the government is under all-round attack over corruption with 2G spectrum, coal block allocation and Commonwealth Games scams being the notorious cases.

Singh said a clear and unambiguous definition of corruption, "covering both the supply and demand sides", is being sought to be provided through amendments to plug gaps in the Prevention of Corruption Act.

"I would like to stress upon the need to protect honest public servants and keep the morale of the Executive intact with our commitment," he said.

Apparently referring to the relentless raking up of corruption issue by opposition parties and civil activists, the Prime Minister said, "The mindless atmosphere of negativity and pessimism that is sought to be created over the issue of corruption can do us no good. It can only damage the nation's image and hit the morale of the Executive."

Asking investigative agencies to continue upgrading their skills and methods to "match the newer methods of corruption", he said, "We need to ensure that even while the corrupt are relentlessly pursued and brought to book, the innocent are not harassed.

"The importance of making a distinction between bonafide mistakes and colorable exercise of power in investigation of corruption cases cannot be over emphasized."

He even advised CBI and other anti-corruption agencies to engage professionals who have expertise which can assist them in conducting an impartial inquiry in complex cases.

"Institutions established with special focus on economic offences should perhaps be more broad-based and need not be confined only to persons with policing background. An open mind in this regard could help imparting credibility to investigations and securing high conviction rates," Singh said.