Investor confidence in Europe fell dramatically in September due to rising concern over the threat of war against Iraq, according to a survey conducted by UBS and the Gallup organisation.

'The Index of Optimism' looks at investor attitudes in Italy, Germany, France, Spain and the UK. The survey is based on more than 1,000 interviews with investors with assets of at least €10,000 ($9,800). Overall, the index fell by 23 points to a level of -24 in September, down from -1 in August, the highest month-to-month decrease ever.