Excessively skinny fashion models will be barred from a major Madrid fashion show later this month for fear they could send the wrong message to young Spanish girls, local media reported.

Madrid's regional government, which is co-financing the Pasarela Cibeles, has vetoed around a third of the models who took part in last year's show because they weigh too little.

The authorities collaborated with a Spanish health organisation to come up with a minumum body mass -- a height-weight ratio -- of 18 for the models.

Spanish daily ABC said it was the first time such restrictions had been imposed on a fashion show, although a recent wedding dress exhibition in Barcelona banned fashion models who took a dress size below 38 (British size 10, US size eight).

Several models at last year's show provoked a row when they claimed their careers would be under threat if they put on weight.

Organisers said they wanted to "help ensure public opinion does not associate fashion, and fashion shows in particular, with an increase in anorexia, a disease which, along with bulimia, is considered ... as a mental and behavioural problem".

The event will take place on September 18-22.