The French say they need the largest condoms in Europe while Greeks get by on smaller ones, according to a Europe-wide study by a German consultancy that provides advice on condoms.

The study by the Singen-based Institute of Condom Consultancy was done by asking 10,500 men in 25 countries to measure their penis and enter the number into a database.

The results show Frenchmen on average claim to need 15.48-cm (6.09-inch) long condoms, about 3 cm longer than Greeks, whose condom-size requirement was the most modest.

Jan Vinzenz Krause, the institute's director, told Reuters Friday the data was collected over a period of eight months.

He did not want to comment on how honest he thought the Frenchmen had been in reporting the data.

The survey was aimed at educating youngsters about the importance of effective contraception.

The institute also offers online condom-size advice and hosts "Pimp Your Condom" -- an annual fair organised in cooperation with the national Aids Trust -- with the aim of educating teens about sexually transmitted diseases.

Krause was in the spotlight in the past when he produced a prototype of the "spray-on condom" -- an aerosol can which contains latex that creates a perfectly fitting condom. But the idea was not developed further.