The number of female corporate leaders in Japan fell for the first time in 25 years in 2005 to 67,299, down 604 from the previous year, according to a survey by a private credit research company.

The ratio of female presidents, however, edged up 0.04 point to 5.71 percent, Teikoku Databank said Thursday. The figure rose for the 25th consecutive year.

According to the survey, the average age of female presidents was 61 years and two months -- two years and five months older than the overall average, including male company presidents.

Teikoku Databank attributed the drop in the number of female presidents to an increase in the number retiring due to old age.

The survey covered 1,179,369 company presidents nationwide.