Brian M. Roddick, Individually and As Representative of Allindividual Subscribers to an Alleged Policy of Insuranceha781490; Indemnity Marine Assurance Company, Ltd; Phoenixassurance Plc; Commercial Union Assurance Company Plc; Lareunion Francaise Soc. Anon D'assurances et De Reassurances;yorkshire Insurance Co. Ltd.; Threadneedle Insurance Co.ltd.; Northern Assurance Co. Ltd; English & Americaninsurance Co. Ltd.; Lombard Continental Insurance Plc;hansa Marine Insurance Co. Ltd.; Polaris Assurance A/s,plaintiffs-appellants, v. Marsh & Mclennan, Incorporated, Defendant-appellee