1 EXHIBIT 15 ACKNOWLEDGMENT LETTER OF INDEPENDENT AUDITORS Shareholders and Board of Directors KeyCorp We are aware of the incorporation by reference in the following KeyCorp ("Key") Registration Statements of our review report, dated July 14, 1998, relating to the unaudited condensed consolidated interim financial statements of Key, included in the Quarterly Report on Form 10-Q for the quarter ended June 30, 1998. Form S-3 No. 33-10634 Form S-3 No. 33-56881 Form S-3 No. 33-58405 Form S-3 No. 333-10577 Form S-3 No. 333-37287 Form S-3 No. 333-55959 Form S-3 No. 333-59175 Form S-4 No. 33-31569 Form S-4 No. 33-44657 Form S-4 No. 33-51717 Form S-4 No. 33-55573 Form S-4 No. 33-57329 Form S-4 No. 33-61539 Form S-4 No. 333-19151 Form S-4 No. 333-61025 Form S-8 No. 2-97452 Form S-8 No. 33-21643 Form S-8 No. 33-42691 Form S-8 No. 33-45518 Form S-8 No. 33-46278 Form S-8 No. 33-52293 Form S-8 No. 33-54819 Form S-8 No. 33-56745 Form S-8 No. 33-56879 Form S-8 No. 333-49609 Form S-8 No. 333-49633 Form S-8 No. 33-31569 (Post-Effective Amendment No. 1 to Form S-4) Form S-8 No. 33-44657 (Post-Effective Amendment No. 1 to Form S-4) Form S-8 No. 33-51717 (Post-Effective Amendment No. 1 to Form S-4) Pursuant to Rule 436(c) of the Securities Act of 1933, our report is not a part of the Registration Statements prepared or certified by accountants within the meaning of Section 7 or 11 of the Securities Act of 1933. /s/ Ernst & Young LLP Cleveland, Ohio August 7, 1998 48