Exhibit 99.4 Trenwick Group Ltd. Trenwick Group Ltd. List of non-Debtor Entities Trenwick (Barbados) Ltd. Trenwick Services Inc. Trenwick America Reinsurance Corporation The Insurance Corporation of New York Chartwell Advisors Limited Canterbury Financial Group Inc. Trenwick Services Ltd. Trenwick Guaranty Insurance Company Ltd. LaSalle Re Limited LaSalle Re (Services) Limited LaSalle Re Corporate Capital Limited LaSalle Re (Barbados) Limited LaSalle (UK) Limited Trenwick UK Holdings Limited Trenwick Holdings Limited Trenwick Underwriting Limited Trenwick UK plc ISIS Consulting Inc. Bowman Loss Adjusters Ltd. Castle Members Agents Limited Archer Personal Lines Limited Castle Underwriting Holdings Limited Surveyors Direct Limited Archer Dedicated plc Adit Holdings Ltd.