LONDON (Standard & Poor's) Aug. 11, 2004--Standard & Poor's Ratings Services said today it assigned its 'BBB' long-term senior unsecured debt rating to the 6.0% securities to be issued by Bermuda-based Aspen Insurance Holdings Ltd. (Aspen Insurance Holdings; BBB/Stable/--). The issue of $250 million is due in 2014. The rating reflects the fact that the securities constitute senior, unsecured general obligations of Aspen Insurance Holdings and will rank equally with all its other senior unsecured indebtedness. The rating on Aspen Insurance Holdings reflects its position as the holding company of the Aspen group, the principal operating subsidiaries of which are U.K.-based Aspen Insurance U.K. Ltd. (A/Stable/--) and Bermuda-based Aspen Insurance Ltd. (A/Stable/--). The rating also reflects key features of the