
<PAGE>   1
 
                         NOTICE OF GUARANTEED DELIVERY
                                 FOR TENDER OF
                           7.826% CAPITAL SECURITIES
                (LIQUIDATION AMOUNT $1,000 PER CAPITAL SECURITY)
                                       OF
 
                        KEYCORP INSTITUTIONAL CAPITAL A
 
   
     As set forth in the Prospectus dated February   , 1997 (the "Prospectus"),
of KeyCorp Institutional Capital A (the "Issuer") and KeyCorp (the
"Corporation") under the caption "The Exchange Offer -- Procedures for Tendering
Old Capital Securities -- Guaranteed Delivery," this form must be used to accept
the Issuer's offer to exchange its 7.826% Capital Securities (the "New Capital
Securities") for a like Liquidation Amount of its outstanding 7.826% Capital
Securities (the "Old Capital Securities"), by Holders who wish to tender their
Old Capital Securities and (i) whose Old Capital Securities are not immediately
available or (ii) who cannot deliver their Old Capital Securities, the Letter of
Transmittal or an Agent's Message (as defined in the Prospectus) and any other
documents required by the Letter of Transmittal to the Exchange Agent prior to
the Expiration Date. This form must be delivered by mail or hand delivery or
transmitted, via facsimile, to the Exchange Agent at its address set forth below
not later than the Expiration Date. All capitalized terms used herein but not
defined herein shall have the meanings ascribed to them in the Prospectus.
    
 
                             THE EXCHANGE AGENT IS:
                             BANKERS TRUST COMPANY
 
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            BY MAIL:                           BY HAND:                 BY OVERNIGHT MAIL OR COURIER:
   BT Services Tennessee, Inc.           Bankers Trust Company           BT Services Tennessee, Inc.
       Reorganization Unit         Corporate Trust and Agency Group   Corporate Trust and Agency Group
         P.O. Box 292737               Receipt & Delivery Window             Reorganization Unit
    Nashville, TN 37229-2737       123 Washington Street, 1st Floor        648 Grassmere Park Road
                                          New York, NY 10006                 Nashville, TN 37211
                                         FOR INFORMATION CALL:
                                            (800) 735-7777
                                        Confirm: (615) 835-3572
                                       Facsimile: (615) 835-3701
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     DELIVERY OF THIS INSTRUMENT TO AN ADDRESS OTHER THAN AS SET FORTH ABOVE OR
TRANSMISSION VIA A FACSIMILE NUMBER OTHER THAN THE ONE LISTED ABOVE WILL NOT
CONSTITUTE A VALID DELIVERY.
 
Ladies and Gentlemen:
 
     The undersigned hereby tenders for exchange to the Issuer upon the terms
and subject to the conditions set forth in the Prospectus and the Letter of
Transmittal, receipt of which is hereby acknowledged, the aggregate Liquidation
Amount of Old Capital Securities set forth below pursuant to the guaranteed
delivery procedures set forth in the Prospectus under the caption "The Exchange
Offer -- Procedures for Tendering Old Capital Securities -- Guaranteed Delivery
Procedures."
 
   
     The undersigned understands and acknowledges that the Exchange Offer will
expire at 5:00 p.m., New York City time, on March   , 1997, unless extended by
the Issuer. The term "Expiration Date" shall mean 5:00 p.m., New York City time,
on March   , 1997, unless the Exchange Offer is extended as provided in the
Prospectus, in which case the term "Expiration Date" shall mean the latest date
and time to which the Exchange Offer is extended.
    
 
     All authority conferred or agreed to be conferred by this Notice of
Guaranteed Delivery shall survive the death, incapacity or dissolution of the
undersigned, and every obligation of the undersigned under this Notice of
Guaranteed Delivery shall be binding upon the undersigned's heirs, personal
representatives, successors and assigns.
<PAGE>   2
 
                                   SIGNATURE
 
X ______________________________________________________  Date: ____________
 
X ______________________________________________________  Date: ____________
Signature(s) of Registered Holders(s) 
or Authorized Signatory
 
Area Code and Telephone Number: ____________________________________________
 
Name(s) ____________________________________________________________________
                                     (Please Print)
 
Capacity (full title, if signing in a fiduciary or representative capacity):
 
____________________________________________________________________________
 
Address: ___________________________________________________________________
                                 (Including Zip Code)
Taxpayer Identification or
Social Security No: ________________________________________________________


Aggregate Liquidation Amount of
Old Capital Securities Tendered
(must be in integral
multiples of $1,000): $ ____________________________________________________
 


Certificate Number(s) of Old Capital Securities (if available):
 

Aggregate Liquidation Amount
Represented by Certificates(s): $ __________________________________________
 
IF TENDERED OLD CAPITAL SECURITIES WILL BE DELIVERED BY BOOK-ENTRY TRANSFER,
PROVIDE THE DEPOSITORY TRUST COMPANY ("DTC") ACCOUNT NO. AND TRANSACTION CODE
NUMBER (IF AVAILABLE):
 
Account No. _________________________________________________________________
 
Transaction No. _____________________________________________________________

 
                              GUARANTY OF DELIVERY
                    (NOT TO BE USED FOR SIGNATURE GUARANTEE)
 
     The undersigned, a firm or entity identified as an "eligible guarantor
institution" within the meaning of Rule 17Ad-15 promulgated under the Securities
Exchange Act of 1934, as amended, guarantees deposit with the Exchange Agent of
a properly completed and executed Letter of Transmittal (or facsimile thereof),
or an Agent's Message, as well as the certificate(s) representing all tendered
Old Capital Securities in proper form for transfer, or confirmation of the
book-entry transfer of such Old Capital Securities into the Exchange Agent's
account at the Book-Entry Transfer Facility described in the Prospectus under
the caption "The Exchange Offer -- Procedures for Tendering Old Capital
Securities -- Book-Entry Transfer" and other documents required by the Letter of
Transmittal, all by 5:00 p.m., New York City time, on the fifth New York Stock
Exchange trading day following the Expiration Date.
 
Name of Eligible Institution: ________________________________________________
 
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                                                AUTHORIZED SIGNATURE

Address:_____________________________________   Name:_________________________

_____________________________________________   Title:________________________

Area Code and Telephone No.:_________________   Date:_________________________
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     NOTE: DO NOT SEND OLD CAPITAL SECURITIES WITH THIS NOTICE. ACTUAL SURRENDER
OF OLD CAPITAL SECURITIES MUST BE PURSUANT TO, AND BE ACCOMPANIED BY, A PROPERLY
EXECUTED LETTER OF TRANSMITTAL.
