The practice deprives women, ethnic and religious minorities and migrants of equal jobs or pay, it claims.

"There is not one country in the world that can say it is free of this problem," Manuela Tomei, the report's author, told a news conference in Geneva.

While the most blatant types of discrimination were fading, "subtle, less visible and more insidious forms" had emerged, including pre-employment testing for HIV/Aids, the report said.

There is not one country in the world that can say it is free of this problem Manuela Tomei ILO

"Every day, around the world, discrimination at work is an unfortunate reality for hundreds of millions of people," said the organisation's Director-General, Juan Somavia, in an introduction to the report.

According to the report, Time for Equality, the most common targets of discrimination are:

• Women, held back by the "glass ceiling" effect imposing arbitrary limits

• HIV/Aids sufferers - 42 million across the world - who face pre-employment testing and then rejection

• People with disabilities, making up to 10% of the world's population, who are denied jobs, training and education

• Believers in minority faiths.

Some 158 of the ILO's 175 member states have ratified a convention protecting workers from exclusion or preference on grounds of race, colour, religion and political opinion.

But the United States, China, and Japan, as well as Singapore and Thailand, are among states yet to sign up.

The report does acknowledge some success from legislation in Europe and North America over several years, and more recent measures introduced in India and post-apartheid South Africa.

Many individual members of minority groups - black Americans, Australian aborigines, Gypsies in Europe, or people at the bottom of the caste system in India and Nepal - have benefited from affirmative action and other anti-discrimination measures.

Affirmative action is necessary, but insufficient Manuela Tomei ILO

How to combat discrimination more effectively, though, is the subject of much disagreement.

"Affirmative action is necessary, but insufficient. It has, of course, to be complemented with other social policy measures," said Ms Tomei.

Governments should do more to convince employers that ending discrimination makes good sense, she said.

ILO studies in Australia found companies that wholeheartedly applied equal opportunities policies increased the productivity of their workers, she said.

The ILO also cited research in the US which found that firms with affirmative action programmes also had more streamlined and efficient recruitment procedures for all their employees.

In most nations, companies are no longer allowed to state in job advertisements that they refuse applications because of race or gender, Ms Tomei said.

"Advertisements might now ask for people who look good, or have a pleasant appearance," she said.

But this was often code language meant to exclude minorities.

Your reaction

All applications are met with an extremely polite, politically correct regret letter Surajit Mukherjee, New Zealand

The nature of discrimination here is extremely subtle. As a migrant on a skills visa with a postgraduate degree in management and several years of senior level corporate experience, I had to take up a job in a casino as a dealer to survive. I got this job through an open day interview - the only job interview that I could get in a six month period. All applications are met with an extremely polite, politically correct regret letter. Executive recruitment firms are briefed to reject anyone with a different sounding name at the shortlisting stage itself. I got wise to this process fast enough and returned to India to take up job immediately at a level commensurate level to my background.
Surajit Mukherjee, New Zealand

One area that the US still has problems is discrimination based on appearance...typically related to size (both weight and height). In most of the US, it is perfectly legal to discriminate against somebody because they are overweight, or extremely short or tall. Fat women are also more likely to be underpaid and underemployed. With the average American woman wearing a size 14 (16 in UK sizes), this becomes an even greater burden that women face.
Karla, USA

Much overlooked is discrimination based on age. This problem will become increasingly important as the proportion of older workers increases, particularly in the more developed countries. It is vital that governments in such countries adopt visionary policies and provide incentives for companies to employ older people. The alternative is for an increasing number of older people to burden the social and pension facilities of these countries, to the point that these facilities collapse
P. Edwards, Switzerland