"The world respects our democracy, our plural and secular values, our independent judiciary...our pursuit of equitable and inclusive growth. But pervasive corruption in our country tarnishes our image.

"It also discourages investors, who expect fair treatment and transparent dealings. As the country grows and integrates with the world economy, corruption continues to be an impediment to harnessing the best of technology and resources," he told the 17th biennial conference of CBI and state anti-corruption bureaux here.

Stressing on the urgent need to combat the menace of corruption, the Prime Minister said "corruption distorts the rule of law and weakens institutions. It hurts our economic growth in a variety of ways, apart from hindering our efforts to build a just, fair and equitable society."

Seeking effective participation of the CBI and officers of various state governments in "war against corruption", he said "the malaise of corruption, so sapping our efforts to march ahead as a nation, should be treated immediately and effectively."

The Prime Minister asked anti-corruption officials to aggressively pursue "high level corruption" and change the perception that "big fish" escape punishment.

"High-level corruption should be pursued aggressively. There is a pervasive feeling that while petty cases get tackled quickly, the big fish escape punishment. This has to change," he said.

The Prime Minister said while quick investigation was important and necessary, it was not sufficient to bring the guilty to book.

"Trials should be conducted expeditiously and judgements delivered quickly. To begin with the aim should be to conclude the trial in two years so that punishment could be given to offenders within a period of three years or so," he said.

Singh said the government has recently decided to set up 71 new CBI courts and expected them to function as model courts, hold day-to-day proceedings and avoid unnecessary adjournments.

The Prime Minister said there is a constant refrain in public discourse that much of what the government provides never reaches the intended beneficiaries -- whether it is subsidised food grains for the poor, loans, fertilisers or seeds on concessional terms for small and marginal farmers or the benefit of employment programmes for the unemployed.

"This should be a matter of serious concern for all of us collectively," he said.