The cost of corruption represents five percent of the world economy -- or more than 1.5 trillion dollars a year, according to World Bank figures published at a UN conference on corruption.

Daniel Kaufman, director of global governance at the World Bank Institute told reporters on Wednesday that the figures were an approximate calculation --

since corruption was largely clandestine -- yet "realistic".

At the close of the second day of the conference of ministers and government officials from some 125 UN member states, a total of 87 governments had signed the first UN Convention Against Corruption.

The convention must be ratified by a minimum of 30 national assemblies before it can go into effect. It is the first document of its

kind that is expected to have a global impact.

The convention is a breakthrough, as signers agree to return assets obtained through corruption and assist each others by providing evidence, freezing bank accounts, confiscating property and extraditing suspects.

It also requires signers to beef up and enforce anti-corruption laws, and to include internationally recognized concepts such as money laundering and influence peddling.

The convention treats corruption as something more than a simple crime, saying it destabilizes countries, slows development and erodes democratic institutions, such as elections.

On the other hand, it states that corruption is often driven by poverty which needs to be addressed globally.

Signatory governments commit to conducting business transparently, to hire and promote on merit and to streamline bureaucracies.

The drafting committee began its work in January 2002 and 128 UN members are collaborating in developing the convention.

The United Nations has distributed a manual with 44 legal, economical and political recommendations for countries to fight corruption.

Conference speakers included Transparency International president Peter Eigen, who said the organization's offices around the world were available to provide help and participate in overseeing the recommendations.

Eigen noted, for example, that no country had yet found a final solution to pesky issues such as financing political campaigns.

Spanish anti-corruption prosecutor Carlos Castresana said international juridical assistance under the Convention provides

tools for tracking private and state corruption cases to court.

Castresana said people should pressure governments as voters, and companies as consumers "to become a (kind of) alternative court of moral condemnation (that would act) as a counterweight to money, " which he described as the root of corruption.