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 Oak Dedicated Limited Oak Dedicated Two Limited Oak Dedicated Three Limited LaSalle Re (Barbados) Limited Trenwick UK Holdings Limited Trenwick Holdings Limited Acorn Corporate Capital Limited Trenwick Underwriting Trenwick UK plc ISIS Consulting Inc. Trenwick Managing Agents Limited Bowman Loss Adjusters Ltd. Trenwick UK Management Services Limited Trenwick UK Pension Trustees Limited Target Insurance Company (Gernsey) Ltd. Castle Members Agents Limited Resource Underwriting Pacific Pty Ltd. Archer Personal Lines Limited Castle Underwriting Holdings Limited Surveyors Direct Limited Trenwick Underwriting Limited Archer Dedicated plc Adit Holdings Ltd. Oak Dedicated Four Limited