<PAGE>
FORM 8-K/A
(Amendment No. 1)
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported) October 6, 1998
--------------------------------
BANK ONE CORPORATION
- --------------------------------------------------------------------------------
(Exact name of registrant as specified in its charter)
Delaware 333-60313 31-1597175
- --------------------------------------------------------------------------------
(State or other jurisdiction (Commission (IRS Employer
of incorporation) File Number) Identification No.)
One First National Plaza, Chicago, IL 60670
- --------------------------------------------------------------------------------
(Address of principal executive offices) (ZIP Code)
Registrant's telephone number, including area code 312-732-4000
------------
<PAGE>
Item 7. Financial Statements and Exhibits
The Registrant hereby substitutes the following table for the table set forth
on page 1 of Exhibit 99(a) to its Current Report on Form 8-K, dated October 6,
1998. Such Form 8-K, including all exhibits thereto, remains unchanged in all
other respects.
<TABLE>
<CAPTION>
Short-Term Senior
Debt Long-Term Debt
-------------------------- -------------------------
S & P Moody's S & P Moody's
---------- ----------- ---------- -----------
<S> <C> <C> <C> <C>
BANK ONE (Parent) A-1 P-1 A+ Aa3
Principal Banks A-1+ P-1 AA- Aa2
</TABLE>
Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.
BANK ONE CORPORATION
---------------------
(Registrant)
Date: October 16, 1998 By: /s/ M. Eileen Kennedy
------------------- ------------------------------------
Title: Treasurer
2