EXHIBIT 15 Acknowledgment Letter To the Stockholders and Board of Directors NAC Re Corporation We are aware of the incorporation by reference in the Registration Statements (Form S-8 No. 33-25585 and Form S-8 No. 33-77494) pertaining to the NAC Re Corp. Employee Stock Purchase Plan, in the Registration Statement (Form S-8 No. 33-27745) pertaining to the NAC Re Corp. 1989 Stock Option Plan, in the Registration Statement (Form S-8 No. 7813) pertaining to the NAC Re Corp. 1985 and 1986 Stock Option Plans, in the Registration Statements (Form S-8 No. 33-22841 and Form S-8 No. 333-03935) pertaining to the NAC Re Corp. Employee Savings Plan, in the Registration Statement (Form S-8 No. 33-34516) pertaining to the NAC Re Corp. Director's Stock Option Plan, in the Registration Statement (Form S-8 No. 33-77492) pertaining to the NAC Re Corp. Director's Stock Option Plan, and in the Registration Statement (Form S-8 No. 33-77114) pertaining to the NAC Re Corp. 1993 Stock Option Plan of our report dated July 22, 1997, relating to the unaudited consolidated interim financial statements of NAC Re Corporation that is included in its Form 10-Q for the quarter ended June 30, 1997. ERNST & YOUNG LLP New York, New York July 22, 1997