A health counselor shows Indian truck drivers how to use a condom along a national highway in Nelamangala, January 2005. [AFP/file]

New Delhi - Condoms designed to meet international size specifications are too big for many Indian men as their penises fall short of what manufacturers had anticipated, an Indian study has found.

The Indian Council of Medical Research, a leading state-run center, said its initial findings from a two-year study showed 60 percent of men in the financial capital Mumbai had penises about 2.4 cm (one inch) shorter than those condoms catered for.

For a further 30 percent, the difference was at least 5 cm (two inches). A poor fit meant the prophylactics often didn't do the job they were bought for, and led to some tearing or slipping off during use.

"One of the reasons for a failure of up to 20 percent (of condoms) is the association of the size of the condom to the erect penis," the council's Dr. Chander Puri told Reuters, adding another reason was couples often put them on in a hurry.

Puri said many men in India, which has the world's highest HIV positive caseload, were too shy to ask for condoms.

"We need more vending machines for condoms of different sizes so people can pick a condom with confidence that is suited to their needs," he said.

The Times of India reported the ICMR survey had studied 1,400 men between 18-50 years of age in cities like Mumbai and New Delhi as well as in rural areas in a report. It entitled its story "Indian men don't measure up."