<PAGE>
                                                                 Exhibit 4(j)

                               GUARANTEE AGREEMENT

                        DATED AS OF _______________, 20__

                                 BY AND BETWEEN

                              ASSOCIATED BANC-CORP,
                                  AS GUARANTOR

                                       AND

                           BNY MIDWEST TRUST COMPANY,
                                   AS TRUSTEE



<PAGE>

                    CROSS REFERENCE TABLE(1)
<TABLE>
<CAPTION>

Section of Trust                                                   Section of
Indenture Act of                                                    Guarantee
1939, as Amended                                                    Agreement

<S>                                                                <C>
310(a).................................................................4.1(a)
310(b)............................................................2.8; 4.1(c)
310(c).........................................................Not Applicable
311(a).................................................................2.2(b)
311(b).................................................................2.2(b)
311(c).........................................................Not Applicable
312(a)............................................................2.2(a); 2.9
312(b)............................................................2.2(b); 2.9
312(c)....................................................................2.9
313(a)....................................................................2.3
313(b)....................................................................2.3
313(c)....................................................................2.3
313(d)....................................................................2.3
314(a)....................................................................2.4
314(b).........................................................Not Applicable
314(c)....................................................................2.5
314(d).........................................................Not Applicable
314(e)....................................................................2.5
314(f).........................................................Not Applicable
315(a)...........................................................1(d); 3.2(a)
315(b).................................................................2.7(a)
315(c).................................................................3.1(c)
315(d).................................................................3.1(d)
316(a)............................................................2.6; 5.4(a)
316(b)....................................................................5.3
316(c).........................................................Not Applicable
317(a)...................................................................2.10
317(b).........................................................Not Applicable
318(a).................................................................2.1(b)
</TABLE>

(1)  This Cross-Reference Table does not constitute part of the Agreement and
     shall not have any bearing upon the interpretation of any of its terms or
     provisions.

                                       i
<PAGE>



                                                 TABLE OF CONTENTS
<TABLE>
<CAPTION>

                                                                            PAGE
                                                                            ----
<S>                                                                         <C>
ARTICLE 1  INTERPRETATION AND DEFINITIONS.....................................1

1.1      Interpretation and Definitions.......................................1

ARTICLE 2  TRUST INDENTURE ACT................................................5

2.1.     Trust Indenture Act; Application.....................................5
2.2.     Lists of Holders of Securities.......................................5
2.3.     Reports by Guarantee Trustee.........................................5
2.4.     Periodic Reports to Guarantee Trustee................................6
2.5.     Evidence of Compliance with Conditions Precedent.....................6
2.6.     Guarantee Event of Default; Waiver...................................6
2.7.     Guarantee Event of Default; Notice...................................6
2.8.     Conflicting Interests................................................6
2.9.     Disclosure of Information............................................6
2.10.    Guarantee Trustee May File Proofs of Claim...........................7

ARTICLE 3  POWERS, DUTIES AND RIGHTS OF GUARANTEE TRUSTEE.....................7

3.1.     Powers and Duties of Guarantee Trustee...............................7
3.2.     Certain Rights of Guarantee Trustee..................................8

ARTICLE 4  GUARANTEE TRUSTEE.................................................10

4.1.     Guarantee Trustee; Eligibility......................................10
4.2.     Appointment, Removal and Resignation of Guarantee Trustee...........11

ARTICLE 5  GUARANTEE.........................................................11

5.1.     Guarantee...........................................................11
5.2.     Waiver of Notice and Demand.........................................12
5.3.     Obligations Not Affected............................................12
5.4.     Rights of Holders...................................................13
5.5.     Guarantee of Payment................................................13
5.6.     Subrogation.........................................................13
5.7.     Independent Obligations.............................................14
</TABLE>


                                       ii

<PAGE>

<TABLE>

<S>                                                                         <C>
ARTICLE 6  LIMITATION OF TRANSACTIONS; SUBORDINATION.........................14

6.1.     Limitation of Transactions..........................................14
6.2.     Ranking.............................................................14
6.3.     Subordination of Common Securities..................................14

ARTICLE 7  TERMINATION.......................................................15

7.1.     Termination.........................................................15

ARTICLE 8  INDEMNIFICATION...................................................15

8.1      Indemnification.....................................................15

ARTICLE 9 MISCELLANEOUS......................................................15

9.1.     Successors and Assigns..............................................15
9.2.     Amendments..........................................................15
9.3.     Notices.............................................................15
9.4.     Benefit.............................................................16
9.5.     Governing Law.......................................................16
</TABLE>


                                      iii
<PAGE>

                               GUARANTEE AGREEMENT

         This GUARANTEE AGREEMENT (the "Guarantee"), dated as of ______ __,
20___, is executed and delivered by ASSOCIATED BANC-CORP, a Delaware corporation
(the "Guarantor"), and BNY MIDWEST TRUST COMPANY, an Illinois banking
corporation, as trustee (the "Guarantee Trustee"), for the benefit of the
Holders (as defined herein) from time to time of the Securities (as defined
herein) of ASBC CAPITAL ______, a Delaware statutory business trust (the
"Trust").

                                    RECITALS

         A. Pursuant to the Trust Agreement (as defined herein), the Trust may
issue up to $___________ aggregate liquidation amount of capital securities,
having a liquidation amount of $___ per security and designated the "_____%
Trust Preferred Securities" of the Trust (the "Capital Securities") and up to
$_____________ aggregate liquidation amount of common securities, having a
liquidation amount of $___ per security and designated the "_____% Common
Securities" of the Trust (the "Common Securities" and, together with the Capital
Securities, the "Securities");

         B. As incentive for the Holders to purchase the Securities, the
Guarantor desires irrevocably and unconditionally to agree, to the extent set
forth in this Guarantee, to pay to the Holders of the Securities the Guarantee
Payments (as defined herein) and to make certain other payments on the terms and
conditions set forth herein; and

         C. If a Trust Enforcement Event (as defined herein) has occurred and is
continuing, the rights of holders of the Common Securities to receive Guarantee
Payments (as defined herein) under this Guarantee are subordinated to the rights
of Holders of Capital Securities to receive Guarantee Payments under this
Guarantee;

                                   AGREEMENTS

         In consideration of the purchase by each Holder of Securities, which
purchase the Guarantor hereby agrees shall benefit the Guarantor, the Guarantor
executes and delivers this Guarantee for the benefit of the Holders.

                                    ARTICLE 1

                         INTERPRETATION AND DEFINITIONS

         1.1. Interpretation and Definitions. In this Guarantee, unless the
context otherwise requires:

              (a) capitalized terms used in this Guarantee but not defined in
the preamble above have the respective meanings assigned to them in this Section
1.1;

              (b) a term defined anywhere in this Guarantee has the same meaning


<PAGE>

throughout;

              (c) all references to "the Guarantee" or "this Guarantee" are to
this Guarantee as modified, supplemented or amended from time to time;

              (d) all references in this Guarantee to Articles, Sections and
Recitals are to Articles, Sections and Recitals of this Guarantee, unless
otherwise specified;

              (e) unless otherwise defined in this Guarantee, a term defined in
the Trust Indenture Act has the same meaning when used in this Guarantee;

              (f) a reference to the singular includes the plural and vice versa
and a reference to any masculine form of a term shall include the feminine form
of a term, as applicable; and

              (g) the following terms have the following meanings:

              "Affiliate" has the same meaning as given to that term in Rule 405
of the Securities Act of 1933, as amended, or any successor rule thereunder.

              "Business Day" has the meaning specified in the Trust Agreement.

              "Capital Securities" has the meaning specified in the Recitals
hereto.

              "Common Securities" has the meaning specified in the Recitals
hereto.

              "Common Stock" means the common stock, par value $0.01 per share,
of the Guarantor.

              "Corporate Trust Office" means the principal office of the
Guarantee Trustee at which at any particular time its corporate trust business
shall be administered, which office at the date of execution of this Guarantee
is located at 2 North LaSalle Street, Suite 1020, Chicago, Illinois 60602.

              "Debentures" means the series of junior subordinated debentures to
be issued by Associated Banc-Corp designated the "______% Junior Subordinated
Debentures due ______ __, ____", held by the Property Trustee as defined in the
Trust Agreement.

              "Extension Period" has the meaning assigned to it in the
Indenture.

              "Global Security" means a fully registered, global Capital
Security, as defined in the Indenture, representing the Capital Securities.

              "Guarantee Event of Default" means a default by the Guarantor on
any of its payment or other obligations under this Guarantee.

              "Guarantee Payments" means the following payments or
distributions, without


                                       2
<PAGE>

duplication, with respect to the Securities, to the extent not paid by or on
behalf of the Trust: (i) any accumulated and unpaid Distributions (as defined in
the Trust Agreement) that are required to be paid on such Securities to the
extent the Trust has sufficient funds available therefor at the time, (ii) the
redemption price, including all accumulated and unpaid Distributions to the date
of redemption, with respect to any Securities called for redemption by the
Trust, to the extent the Trust shall have sufficient funds available therefor at
the time or (iii) upon a voluntary or involuntary dissolution, winding-up or
termination of the Trust (other than in connection with the distribution of
Debentures to the Holders in exchange for Securities as provided in the Trust
Agreement), the lesser of (A) the aggregate of the liquidation amount and all
accumulated and unpaid Distributions on the Securities to the date of payment,
to the extent the Trust has sufficient funds available therefor or (B) the
amount of assets of the Trust remaining available for distribution to Holders in
liquidation of the Trust (in either case, the "Liquidation Distribution").

              "Guarantee Trustee" means BNY Midwest Trust Company, until a
Successor Guarantee Trustee has been appointed and has accepted such appointment
pursuant to the terms of this Guarantee and thereafter means each such Successor
Guarantee Trustee.

              "Holder" means any holder of Securities, as registered on the
books and records of the Trust; provided, however, that, in determining whether
the Holders of the requisite percentage of Capital Securities have given any
request, notice, consent or waiver hereunder, "Holder" shall not include the
Guarantor or any Affiliate of the Guarantor or any other obligor on the Capital
Securities.

              "Indemnified Person" means (a) any Guarantor Trustee; (b) any
Affiliate of any Guarantor Trustee; or (c) any officers, directors,
shareholders, members, partners, employees, representatives or agents of any
Guarantor Trustee or any Affiliate thereof.

              "Indenture" means the Indenture, dated as of __________________,
2002, by and between Associated Banc-Corp and BNY Midwest Trust Company, as
Trustee, and any indenture supplemental thereto pursuant to which the Debentures
are to be issued to the Property Trustee, as defined in the Trust Agreement.

              "List of Holders" has the meaning assigned to it in Section 2.2
hereof.

              "Majority in Liquidation Amount" means, except as provided in the
terms of the Capital Securities or by the Trust Indenture Act, Holder(s) of
outstanding Securities, voting together as a single class, or, as the context
may require, Holders of outstanding Capital Securities or Holders of outstanding
Common Securities, voting separately as a class, who are the record owners of
more than 50% of the aggregate liquidation amount (including the stated amount
that would be paid on redemption, liquidation or otherwise, plus accumulated and
unpaid Distributions to the date upon which the voting percentages are
determined) of all outstanding Securities of the relevant class. In determining
whether the Holders of the requisite amount of Securities have voted, Securities
which are owned by the Guarantor or any Affiliate of the Guarantor or any other
obligor on the Securities shall be disregarded for the purpose of any such
determination.

                                       3
<PAGE>

              "Officers' Certificate" means, with respect to any Person, a
certificate signed on behalf of such Person by two Authorized Officers (as
defined in the Trust Agreement) of such Person; provided, that, with respect to
the Guarantor, such certificate must be signed by the Chairman of the Board of
Directors, the Vice Chairman of the Board of Directors, the President, the Chief
Financial Officer, the Chief Administrative Officer, or a Senior Vice President,
and by the Treasurer, an Assistant Treasurer, the Secretary or an Assistant
Secretary of the Guarantor. Any Officers' Certificate delivered with respect to
compliance with a condition or covenant provided for in this Guarantee shall
include:

              (i) a statement that each officer signing the Officers'
Certificate has read the covenant or condition and the definitions relating
thereto;

              (ii) a brief statement of the nature and scope of the examination
or investigation undertaken by each officer on behalf of such Person in
rendering the Officers' Certificate;

              (iii) a statement that each such officer has made such examination
or investigation as, in such officer's opinion, is necessary to enable such
officer on behalf of such Person to express an informed opinion as to whether or
not such covenant or condition has been complied with; and

              (iv) a statement as to whether, in the opinion of each such
officer acting on behalf of such Person, such condition or covenant has been
complied with.

              "Person" means a legal person, including any individual,
corporation, estate, partnership, joint venture, association, joint stock
company, limited liability company, trust, unincorporated association, or
government or any agency or political subdivision thereof, or any other entity
of whatever nature.

              "Redemption Price" has the meaning specified in the Trust
Agreement.

              "Responsible Officer" means, with respect to the Guarantee
Trustee, any officer with direct responsibility for the administration of this
Guarantee and also means, with respect to a particular corporate trust matter,
any other officer to whom such matter is referred because of that officer's
knowledge of and familiarity with the particular subject.

              "Securities" has the meaning specified in the Recitals hereto.

              "Successor Guarantee Trustee" means a successor Guarantee Trustee
possessing the qualifications to act as Guarantee Trustee under Section 4.1.

              "Trust Agreement" means the Amended and Restated Trust Agreement,
dated as of the date hereof, as amended, modified or supplemented from time to
time, among the trustees of the Trust named therein, the Guarantor, as sponsor,
and the Holders, from time to time, of undivided beneficial ownership interests
in the assets of the Trust.

                                       4
<PAGE>

              "Trust Enforcement Event" in respect of the Securities means an
Indenture Event of Default (as defined in the Indenture) has occurred and is
continuing in respect of the Debentures.

              "Trust Indenture Act" means the Trust Indenture Act of 1939, as
amended from time to time, or any successor legislation.

                                    ARTICLE 2

                               TRUST INDENTURE ACT

         2.1. Trust Indenture Act; Application.

              (a) This Guarantee is subject to the provisions of the Trust
Indenture Act that are required to be part of this Guarantee and shall, to the
extent applicable, be governed by such provisions.

              (b) If and to the extent that any provision of this Guarantee
limits, qualifies or conflicts with the duties imposed by Sections 310 to 317,
inclusive, of the Trust Indenture Act, such imposed duties shall control.

         2.2. Lists of Holders of Securities.

              (a) The Guarantor shall provide the Guarantee Trustee (i) except
while the Capital Securities are represented by one or more Global Securities,
at least two Business Days prior to the date for payment of Distributions, a
list, in such form as the Guarantee Trustee may reasonably require, of the names
and addresses of the Holders of the Securities ("List of Holders") as of the
record date relating to the payment of such Distributions, and (ii) at any other
time, within 30 days of receipt by the Guarantor of a written request from the
Guarantee Trustee for a List of Holders as of a date no more than 15 days before
such List of Holders is given to the Guarantee Trustee; provided that the
Guarantor shall not be obligated to provide such List of Holders at any time the
List of Holders does not differ from the most recent List of Holders given to
the Guarantee Trustee by the Guarantor. The Guarantee Trustee shall preserve, in
as current a form as is reasonably practicable, all information contained in
Lists of Holders given to it, provided that the Guarantee Trustee may destroy
any List of Holders previously given to it on receipt of a new List of Holders.

              (b) The Guarantee Trustee shall comply with its obligations under
Sections 311(a), 311(b) and 312(b) of the Trust Indenture Act.

              2.3. Reports by Guarantee Trustee. Within 60 days after _______
___ of each year (commencing with the year of the first anniversary of the
issuance of the Securities), the Guarantee Trustee shall provide to the Holders
of the Securities such reports as are required by Section 313 of the Trust
Indenture Act (if any) in the form and in the manner provided by Section 313 of
the Trust Indenture Act. The Guarantee Trustee shall also comply with the



                                       5
<PAGE>

requirements of Section 313(d) of the Trust Indenture Act.

         2.4. Periodic Reports to Guarantee Trustee. The Guarantor shall
provide to the Guarantee Trustee such documents, reports and information as
required by Section 314(a) (if any) of the Trust Indenture Act and the
compliance certificate required by Section 314(a) of the Trust Indenture Act in
the form, in the manner and at the times required by Section 314(a) of the Trust
Indenture Act, but in no event later than 120 days after the end of each
calendar year.

         2.5. Evidence of Compliance with Conditions Precedent. The
Guarantor shall provide to the Guarantee Trustee such evidence of compliance
with any conditions precedent, if any, provided for in this Guarantee that
relate to any of the matters set forth in Section 314(c) of the Trust Indenture
Act. Any certificate or opinion required to be given by an officer pursuant to
Section 314(c)(1) of the Trust Indenture Act may be given in the form of an
Officers' Certificate.

         2.6. Guarantee Event of Default; Waiver. The Holders of a Majority
in Liquidation Amount of the Capital Securities may, by vote or written consent,
on behalf of the Holders of all of the Securities, waive any past Guarantee
Event of Default and its consequences. Upon such waiver, any such Guarantee
Event of Default shall cease to exist, and any Guarantee Event of Default
arising therefrom shall be deemed to have been cured, for every purpose of this
Guarantee, but no such waiver shall extend to any subsequent or other default or
Guarantee Event of Default or impair any right consequent thereon.

         2.7. Guarantee Event of Default; Notice.

              (a) The Guarantee Trustee shall, within 90 days after the
occurrence of a Guarantee Event of Default actually known to a Responsible
Officer of the Guarantee Trustee, transmit by mail, first class postage prepaid,
to the Holders of the Securities, notices of all such Guarantee Events of
Default, unless such defaults have been cured before the giving of such notice;
provided, that the Guarantee Trustee shall be protected in withholding such
notice if and so long as a Responsible Officer of the Guarantee Trustee in good
faith determines that the withholding of such notice is in the interests of the
Holders of the Securities.

              (b) The Guarantee Trustee shall not be deemed to have knowledge of
any Guarantee Event of Default unless the Guarantee Trustee shall have received
written notice thereof or a Responsible Officer of the Guarantee Trustee charged
with the administration of this Guarantee Agreement shall have obtained actual
knowledge thereof.

         2.8. Conflicting Interests. The Trust Agreement shall be deemed to
be specifically described in this Guarantee for the purposes of clause (i) of
the first proviso contained in Section 310(b) of the Trust Indenture Act.

         2.9. Disclosure of Information. The disclosure of information as to
the names and addresses of the Holders of the Securities in accordance with
Section 312 of the Trust Indenture Act, regardless of the source from which such
information was derived, shall not be deemed to be a violation of any existing
law, or any law hereafter enacted which does not specifically refer to Section
312 of the Trust Indenture Act, nor shall the Guarantee Trustee be held
accountable by


                                       6
<PAGE>

reason of mailing any material pursuant to a request made under Section 312(b)
of the Trust Indenture Act.

         2.10. Guarantee Trustee May File Proofs of Claim. Upon the occurrence
of a Guarantee Event of Default, the Guarantee Trustee is hereby authorized to
(a) recover judgment, in its own name and as trustee of an express trust,
against the Guarantor for the whole amount of any Guarantee Payments remaining
unpaid and (b) file such proofs of claim and other papers or documents as may be
necessary or advisable in order to have its claims and those of the Holders of
the Securities allowed in any judicial proceedings relative to the Guarantor,
its creditors or its property.

                                    ARTICLE 3

                          POWERS, DUTIES AND RIGHTS OF
                                GUARANTEE TRUSTEE

         3.1. Powers and Duties of Guarantee Trustee.

              (a) This Guarantee shall be held by the Guarantee Trustee on
behalf of the Trust for the benefit of the Holders of the Securities, and the
Guarantee Trustee shall not transfer this Guarantee to any Person except a
Holder of Securities exercising his or her rights pursuant to Section 5.4(b) or
to a Successor Guarantee Trustee on acceptance by such Successor Guarantee
Trustee of its appointment to act as Successor Guarantee Trustee. The right,
title and interest of the Guarantee Trustee in and to this Guarantee shall
automatically vest in any Successor Guarantee Trustee, and such vesting and
succession of title shall be effective whether or not conveyance documents have
been executed and delivered pursuant to the appointment of such Successor
Guarantee Trustee.

              (b) If a Guarantee Event of Default actually known to a
Responsible Officer of the Guarantee Trustee has occurred and is continuing, the
Guarantee Trustee shall enforce this Guarantee for the benefit of the Holders of
the Securities.

              (c) The Guarantee Trustee, before the occurrence of any Guarantee
Event of Default and after the curing of all Guarantee Events of Default that
may have occurred, shall undertake to perform only such duties as are
specifically set forth in this Guarantee, and no implied covenants shall be read
into this Guarantee against the Guarantee Trustee. In case a Guarantee Event of
Default has occurred (that has not been cured or waived pursuant to Section 2.6)
and is actually known to a Responsible Officer of the Guarantee Trustee, the
Guarantee Trustee shall exercise such of the rights and powers vested in it by
this Guarantee, and use the same degree of care and skill in its exercise
thereof, as a prudent person would exercise or use under the circumstances in
the conduct of his or her own affairs.

              (d) No provision of this Guarantee shall be construed to relieve
the Guarantee Trustee from liability for its own negligent action, its own
negligent failure to act, or its own willful misconduct, except that:

                                       7
<PAGE>

                  (i) prior to the occurrence of any Guarantee Event of Default
and after the curing or waiving of all such Guarantee Events of Default that may
have occurred:

                      (A) the duties and obligations of the Guarantee Trustee
shall be determined solely by the express provisions of this Guarantee, and the
Guarantee Trustee shall not be liable except for the performance of such duties
and obligations as are specifically set forth in this Guarantee, and no implied
covenants or obligations shall be read into this Guarantee against the Guarantee
Trustee; and

                      (B) in the absence of bad faith on the part of the
Guarantee Trustee, the Guarantee Trustee may conclusively rely, as to the truth
of the statements and the correctness of the opinions expressed therein, upon
any certificates or opinions furnished to the Guarantee Trustee and conforming
to the requirements of this Guarantee; but in the case of any such certificates
or opinions that by any provision hereof are specifically required to be
furnished to the Guarantee Trustee, the Guarantee Trustee shall be under a duty
to examine the same to determine whether or not they conform to the requirements
of this Guarantee;

                  (ii) the Guarantee Trustee shall not be liable for any error
of judgment made in good faith by a Responsible Officer of the Guarantee
Trustee, unless it shall be proved that the Guarantee Trustee was negligent in
ascertaining the pertinent facts upon which such judgment was made;

                  (iii) the Guarantee Trustee shall not be liable with respect
to any action taken or omitted to be taken by it in good faith in accordance
with the direction of the Holders of not less than a Majority in Liquidation
Amount of the Securities relating to the time, method and place of conducting
any proceeding for any remedy available to the Guarantee Trustee, or exercising
any trust or power conferred upon the Guarantee Trustee under this Guarantee;
and

                  (iv) no provision of this Guarantee shall require the
Guarantee Trustee to expend or risk its own funds or otherwise incur personal
financial liability in the performance of any of its duties or in the exercise
of any of its rights or powers, if the Guarantee Trustee shall have reasonable
grounds for believing that the repayment of such funds or liability is not
reasonably assured to it under the terms of this Guarantee or if the Guarantee
Trustee shall have reasonable grounds for believing that an indemnity,
reasonably satisfactory to the Guarantee Trustee, against such risk or liability
is not reasonably assured to it under the terms of this Guarantee.

         3.2. Certain Rights of Guarantee Trustee.

              (a) Subject to the provisions of Section 3.1:

                  (i) The Guarantee Trustee may conclusively rely, and shall be
fully protected in acting or refraining from acting upon, any resolution,
certificate, statement, instrument, opinion, report, notice, request, direction,
consent, order, bond, debenture, note, other evidence of indebtedness or other
paper or document believed by it to be genuine and to have been signed, sent or
presented by the proper party or parties;

                                       8
<PAGE>

                  (ii) Any direction or act of the Guarantor contemplated by
this Guarantee shall be sufficiently evidenced by an Officers' Certificate;

                  (iii) Whenever, in the administration of this Guarantee, the
Guarantee Trustee shall deem it desirable that a matter be proved or established
before taking, suffering or omitting any action hereunder, the Guarantee Trustee
(unless other evidence is herein specifically prescribed) may, in the absence of
bad faith on its part, request and conclusively rely upon an Officers'
Certificate which, upon receipt of such request, shall be promptly delivered by
the Guarantor;

                  (iv) The Guarantee Trustee shall have no duty to see to any
recording, filing or registration or any instrument (or any rerecording,
refiling or re-registration thereof);

                  (v) The Guarantee Trustee may consult with counsel, and the
advice or opinion of such counsel with respect to legal matters shall be full
and complete authorization and protection in respect of any action taken,
suffered or omitted by it hereunder in good faith and in accordance with such
advice or opinion. Such counsel may be counsel to the Guarantor or any of its
Affiliates and may include any of its employees. The Guarantee Trustee shall
have the right at any time to seek instructions concerning the administration of
this Guarantee from any court of competent jurisdiction;

                  (vi) The Guarantee Trustee shall be under no obligation to
exercise any of the rights or powers vested in it by this Guarantee at the
request or direction of any Holder, unless such Holder shall have provided to
the Guarantee Trustee such security and indemnity, reasonably satisfactory to
the Guarantee Trustee, against the costs, expenses (including attorneys' fees
and expenses and the expenses of the Guarantee Trustee's agents, nominees or
custodians) and liabilities that might be incurred by it in complying with such
request or direction, including such reasonable advances as may be requested by
the Guarantee Trustee; provided, that nothing contained in this Section
3.2(a)(vi) shall be taken to relieve the Guarantee Trustee, upon the occurrence
of a Guarantee Event of Default, of its obligation to exercise the rights and
powers vested in it by this Guarantee;

                  (vii) The Guarantee Trustee shall not be bound to make any
investigation into the facts or matters stated in any resolution, certificate,
statement, instrument, opinion, report, notice, request, direction, consent,
order, bond, debenture, note, other evidence of indebtedness or other paper or
document, but the Guarantee Trustee, in its discretion, may make such further
inquiry or investigation into such facts or matters as it may see fit;

                  (viii) The Guarantee Trustee may execute any of the trusts or
powers hereunder or perform any duties hereunder either directly or by or
through agents, nominees, custodians or attorneys, and the Guarantee Trustee
shall not be responsible for any misconduct or negligence on the part of any
agent or attorney appointed with due care by it hereunder;

                  (ix)  Any action taken by the Guarantee Trustee or its agents
hereunder shall bind the Holders, and the signature of the Guarantee Trustee or
its agents alone shall be



                                       9
<PAGE>

sufficient and effective to perform any such action. No third party shall be
required to inquire as to the authority of the Guarantee Trustee to so act or as
to its compliance with any of the terms and provisions of this Guarantee, both
of which shall be conclusively evidenced by the Guarantee Trustee's or its
agent's taking such action; and

                  (x) Whenever in the administration of this Guarantee, the
Guarantee Trustee shall deem it desirable to receive instructions with respect
to enforcing any remedy or right or taking any other action hereunder, the
Guarantee Trustee (A) may request written instructions from the Holders of a
Majority in Liquidation Amount of the Securities, (B) may refrain from enforcing
such remedy or right or taking such other action until such written instructions
are received and (C) shall be protected in conclusively relying on or acting in
accordance with such written instructions.

              (b) No provision of this Guarantee shall be deemed to impose any
duty or obligation on the Guarantee Trustee to perform any act or acts or
exercise any right, power, duty or obligation conferred or imposed on it in any
jurisdiction in which it shall be illegal, or in which the Guarantee Trustee
shall be unqualified or incompetent to act in accordance with applicable law, to
perform any such act or acts or to exercise any such right, power, duty or
obligation. No permissive power or authority available to the Guarantee Trustee
shall be construed to be a duty.

                                    ARTICLE 4

                                GUARANTEE TRUSTEE

         4.1. Guarantee Trustee; Eligibility.

              (a) There shall be at all times a Guarantee Trustee which shall:

                  (i) not be an Affiliate of the Guarantor; and

                  (ii) be a corporation organized and doing business under the
laws of the United States of America or any state or territory thereof or of the
District of Columbia, or a corporation or other Person permitted by the
Securities and Exchange Commission to act as an institutional trustee under the
Trust Indenture Act, authorized under such laws to exercise corporate trust
powers, having a combined capital and surplus of at least 50 million U.S.
dollars ($50,000,000), and subject to supervision or examination by federal,
state, territorial or District of Columbia authority. If such corporation
publishes reports of condition at least annually, pursuant to law or to the
requirements of the supervising or examining authority referred to above, then,
for the purposes of this Section 4.1(a)(ii), the combined capital and surplus of
such corporation shall be deemed to be its combined capital and surplus as set
forth in its most recent report of condition so published.

              (b) If at any time the Guarantee Trustee shall cease to be
eligible to so act under Section 4.1(a), the Guarantee Trustee shall immediately
resign in the manner and with the effect set out in Section 4.2(c).

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<PAGE>

             .(c) If the Guarantee Trustee has or shall acquire any
"conflicting interest" within the meaning of Section 310(b) of the Trust
Indenture Act, the Guarantee Trustee and Guarantor shall in all respects comply
with the provisions of Section 310(b) of the Trust Indenture Act.

         4.2. Appointment, Removal and Resignation of Guarantee Trustee.

              (a) Subject to Section 4.2(b), unless a Guarantee Event of Default
shall have occurred and be continuing, the Guarantee Trustee may be appointed or
removed with or without cause at any time by the Guarantor.

              (b) The Guarantee Trustee shall not be removed in accordance with
Section 4.2(a) until a Successor Guarantee Trustee has been appointed and has
accepted such appointment by written instrument executed by such Successor
Guarantee Trustee and delivered to the Guarantor.

              (c) The Guarantee Trustee appointed to office shall hold such
office until a Successor Guarantee Trustee shall have been appointed or until
its removal or resignation. The Guarantee Trustee may resign from office
(without need for prior or subsequent accounting) by an instrument in writing
executed by the Guarantee Trustee and delivered to the Guarantor, which
resignation shall not take effect until a Successor Guarantee Trustee has been
appointed and has accepted such appointment by instrument in writing executed by
such Successor Guarantee Trustee and delivered to the Guarantor and the
resigning Guarantee Trustee.

              (d) If no Successor Guarantee Trustee shall have been appointed
and accepted appointment as provided in this Section 4.2 within 60 days after
delivery to the Guarantor of an instrument of removal or resignation, the
removed or resigning Guarantee Trustee may petition any court of competent
jurisdiction for appointment of a Successor Guarantee Trustee. Such court may
thereupon, after prescribing such notice, if any, as it may deem proper, appoint
a Successor Guarantee Trustee.

              (e) No Guarantee Trustee shall be liable for the acts or omissions
to act of any Successor Guarantee Trustee.

              (f) Upon termination of this Guarantee or removal or resignation
of the Guarantee Trustee pursuant to this Section 4.2, the Guarantor shall pay
to the Guarantee Trustee all amounts owing for fees and reimbursement of
expenses which have accrued to the date of such termination, removal or
resignation.

                                    ARTICLE 5

                                    GUARANTEE

         5.1. Guarantee. The Guarantor irrevocably and unconditionally
agrees to pay in full to the Holders the Guarantee Payments (without duplication
of amounts theretofore paid by the


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<PAGE>


Trust), as and when due, regardless of any defense, right of set-off or
counterclaim that the Trust may have or assert. The Guarantor's obligation to
make a Guarantee Payment may be satisfied by direct payment of the required
amounts by the Guarantor to the Holders or by causing the Trust to pay such
amounts to the Holders. Notwithstanding anything to the contrary herein, the
Guarantor retains all of its rights under the Indenture to extend the interest
payment period on the Debentures pursuant to Section 3.11 thereof and the
Guarantor shall not be obligated hereunder to make any Guarantee Payments during
any Extension Period with respect to the Distributions (as defined in the Trust
Agreement) on the Securities.

         5.2. Waiver of Notice and Demand. The Guarantor hereby waives
notice of acceptance of this Guarantee and of any liability to which it applies
or may apply, presentment, demand for payment, any right to require a proceeding
first against the Trust or any other Person before proceeding against the
Guarantor, protest, notice of nonpayment, notice of dishonor, notice of
redemption and all other notices and demands.

         5.3. Obligations Not Affected. The obligations, covenants,
agreements and duties of the Guarantor under this Guarantee shall be absolute
and unconditional and shall remain in full force and effect until the entire
liquidation amount of all outstanding Securities shall have been paid and such
obligation shall in no way be affected or impaired by reason of the happening
from time to time of any event, including without limitation, the following,
whether or not with notice to, or the consent of, the Guarantor:

              (a) The release or waiver, by operation of law or otherwise, of
the performance or observance by the Trust of any express or implied agreement,
covenant, term or condition relating to the Securities to be performed or
observed by the Trust;

              (b) The extension of time for the payment by the Trust of all or
any portion of the Distributions, Redemption Price, Liquidation Distribution or
any other sums payable under the terms of the Securities or the extension of
time for the performance of any other obligation under, arising out of, or in
connection with the Securities (other than an extension of time for payment of
Distributions, Redemption Price, Liquidation Distribution or other sum payable
that results from the extension of any interest payment period on the
Debentures);

              (c) Any failure, omission, delay or lack of diligence on the part
of the Property Trustee or the Holders to enforce, assert or exercise any right,
privilege, power or remedy conferred on the Property Trustee or the Holders
pursuant to the terms of the Securities, or any action on the part of the Trust
granting indulgence or extension of any kind;

              (d) The voluntary or involuntary liquidation, dissolution, sale of
any collateral, receivership, insolvency, bankruptcy, assignment for the benefit
of creditors, reorganization, arrangement, composition or readjustment of debt
of, or other similar proceedings affecting, the Trust or any of the assets of
the Trust;

              (e) Any invalidity of, or defect or deficiency in, the Securities;

              (f) The settlement or compromise of any obligation guaranteed
hereby or

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<PAGE>


hereby incurred; or

              (g) Any other circumstance whatsoever that might otherwise
constitute a legal or equitable discharge or defense of a guarantor, it being
the intent of this Section 5.3 that the obligations of the Guarantor hereunder
shall be absolute and unconditional under any and all circumstances.

              There shall be no obligation of the Guarantee Trustee or the
Holders to give notice to, or obtain consent of the Guarantor or any other
Person with respect to the happening of any of the foregoing.

              No setoff, counterclaim, reduction or diminution of any
obligation, or any defense of any kind or nature that the Guarantor has or may
have against any Holder shall be available hereunder to the Guarantor against
such Holder to reduce the payments to it under this Guarantee.

         5.4. Rights of Holders.


              (a) The Holders of at least a Majority in Liquidation Amount of
the Securities have the right to direct the time, method and place of conducting
any proceeding for any remedy available to the Guarantee Trustee in respect of
this Guarantee or to direct the exercise of any trust or power conferred upon
the Guarantee Trustee under this Guarantee.

              (b) If the Guarantee Trustee fails to enforce this Guarantee, then
any Holder of Securities may, subject to the subordination provisions of Section
6.2, institute a legal proceeding directly against the Guarantor to enforce the
Guarantee Trustee's rights under this Guarantee without first instituting a
legal proceeding against the Trust, the Guarantee Trustee or any other person or
entity. In addition, if the Guarantor has failed to make a Guarantee Payment, a
Holder of Securities may, subject to the subordination provisions of Section
6.2, directly institute a proceeding against the Guarantor for enforcement of
the Guarantee for such payment to the Holder of the Securities of the principal
of or interest on the Debentures on or after the respective due dates specified
in the Debentures, and the amount of the payment will be based on the Holder's
pro rata share of the amount due and owing on all of the Securities. The
Guarantor hereby waives any right or remedy to require that any action on this
Guarantee be brought first against the Trust or any other person or entity
before proceeding directly against the Guarantor.

         5.5. Guarantee of Payment.  This Guarantee creates a guarantee of
payment and not of collection.

         5.6. Subrogation. The Guarantor shall be subrogated to all (if any)
rights of the Holders of Securities against the Trust in respect of any amounts
paid to such Holders by the Guarantor under this Guarantee; provided, however,
that the Guarantor shall not (except to the extent required by mandatory
provisions of law) be entitled to enforce or exercise any right that it may
acquire by way of subrogation or any indemnity, reimbursement or other
agreement, in all cases as a result of payment under this Guarantee, if at the
time of any such payment, any amounts are due and unpaid under this Guarantee.
If any amount shall be paid to the Guarantor


                                       13
<PAGE>

in violation of the preceding sentence, the Guarantor agrees to hold such amount
in trust for the Holders and to pay over such amount to the Guarantee Trustee
for the benefit of the Holders.

         5.7. Independent Obligations. The Guarantor acknowledges that its
obligations hereunder are independent of the obligations of the Trust with
respect to the Securities, and that the Guarantor shall be liable as principal
and as debtor hereunder to make Guarantee Payments pursuant to the terms of this
Guarantee notwithstanding the occurrence of any event referred to in subsections
5.3(a) through 5.3(g), inclusive, hereof.

                                    ARTICLE 6

                    LIMITATION OF TRANSACTIONS; SUBORDINATION

         6.1. Limitation of Transactions. So long as any Securities remain
outstanding, if (a) there shall have occurred an event of default under the
Indenture with respect to the Debentures, (b) there shall be a Guarantee Event
of Default or (c) the Guarantor shall have given notice of its election of an
Extension Period as provided in the certificate evidencing the Debentures and
shall not have rescinded such notice, or such Extension Period or any extension
thereof shall be continuing, then the Guarantor shall not, and shall not permit
any subsidiary of the Guarantor, to (i) declare or pay any dividends or
distributions on, or redeem, purchase, acquire or make a liquidation payment
with respect to, any of the Guarantor's capital stock or (ii) make any payment
of principal, interest or premium, if any, on or repay, repurchase or redeem any
debt securities of the Guarantor that rank pari passu with or junior in interest
to the Debentures or make any guarantee payments with respect to any guarantee
by the Guarantor of the debt securities of any subsidiary of the Guarantor if
such guarantee ranks pari passu with or junior in interest to the Debentures
(other than (A) dividends or distributions in Common Stock of the Guarantor, (B)
any declaration of a dividend in connection with the implementation of a rights
plan or the issuance of stock under any such plan or the redemption or
repurchase of any such rights pursuant thereto, (C) payments under this
Guarantee and (D) purchases of Common Stock related to the issuance of Common
Stock or rights under any of the Company's benefits plans for its directors,
officers or employees).

         6.2. Ranking. This Guarantee will constitute an unsecured obligation
of the Guarantor and will rank subordinate and junior in right of payment to all
Senior and Subordinated Debt (as defined in the Indenture) of the Guarantor in
the same manner and to the same extent as set forth in Article XIII of the
Indenture.

         6.3. Subordination of Common Securities. If a Trust Enforcement
Event has occurred and is continuing under the Trust Agreement, the rights of
the holders of the Common Securities to receive Guarantee Payments hereunder
shall be subordinated to the rights of the Holders of the Capital Securities to
receive Guarantee Payments under this Guarantee.

                                       14
<PAGE>

                                    ARTICLE 7

                                   TERMINATION

         7.1. Termination. This Guarantee shall terminate upon (a) full
payment of the Redemption Price of all Securities, (b) distribution of the
Debentures to the Holders of all the Securities or (c) full payment of the
amounts payable in accordance with the Trust Agreement upon liquidation of the
Trust. Notwithstanding the foregoing, this Guarantee will continue to be
effective or will be reinstated, as the case may be, if at any time any Holder
of Securities must restore payment of any sums paid under the Securities or
under this Guarantee.

                                    ARTICLE 8

                                 INDEMNIFICATION

         8.1. Indemnification. The Guarantor agrees to indemnify each
Indemnified Person for, and to hold each Indemnified Person harmless against any
loss, liability or expense incurred without negligence or bad faith on its part,
arising out of or in connection with the acceptance or administration of the
trust or trusts hereunder, including the reasonable costs and expenses of
defending itself against, or investigating, any claim or liability in connection
with the exercise or performance of any of its powers or duties hereunder. The
provisions of this Section 8.1 shall survive the termination of this Guarantee
or the resignation or removal of the Guarantee Trustee.

                                    ARTICLE 9

                                  MISCELLANEOUS

         9.1. Successors and Assigns. All guarantees and agreements contained
in this Guarantee shall bind the successors, assigns, receivers, trustees and
representatives of the Guarantor and shall inure to the benefit of the Holders
of the Securities then outstanding. Except in connection with a consolidation,
merger or sale involving the Guarantor that is permitted under Article VIII of
the Indenture and pursuant to which the successor or assignee agrees in writing
to perform the Guarantor's obligations hereunder, the Guarantor shall not assign
its obligations hereunder.

         9.2. Amendments. Except with respect to any changes that do not
materially adversely affect the rights of the Holders (in which case no consent
of the Holders will be required), this Guarantee may not be amended without the
prior approval of the Holders of at least a Majority in Liquidation Amount of
the Securities. The provisions of Section 11.2 of the Trust Agreement with
respect to meetings of, and action by written consent of, the Holders of the
Securities apply to the giving of such approval.

         9.3. Notices. All notices provided for in this Guarantee shall be
in writing, duly signed by the party giving such notice, and shall be delivered
by hand, telecopied or mailed by registered or certified mail, as follows:

                                       15
<PAGE>

              (a) If given to the Guarantee Trustee, at the Guarantee Trustee's
mailing address set forth below (or such other address as the Guarantee Trustee
may give notice of to the Guarantor and the Holders of the Securities):

                  BNY Midwest Trust Company
                  2 North La Salle Street,
                  Suite 1020
                  Chicago, Illinois 60602
                  Facsimile No.:

              (b) If given to the Guarantor, at the Guarantor's mailing
addresses set forth below (or such other address as the Guarantor may give
notice of to the Guarantee Trustee and the Holders of the Securities):

                  Associated Banc-Corp
                  1200 Hansen Road
                  Green Bay, Wisconsin 54304
                  Attention:  Brian D. Bodager, Chief Administrative Officer
                  Facsimile No.:  (920) 491-7010

              (c) If given to any Holder of Securities, at the address set forth
on the books and records of the Trust.

              All such notices shall be deemed to have been given when received
in person, telecopied with receipt confirmed, or mailed by first class mail,
postage prepaid, except that if a notice or other document is refused delivery
or cannot be delivered because of a changed address of which no notice was
given, such notice or other document shall be deemed to have been delivered on
the date of such refusal or inability to deliver.

         9.4. Benefit. This Guarantee is solely for the benefit of the
Holders of the Securities and, subject to Section 3.1(a), is not separately
transferable from the Securities.

         9.5. Governing Law. THIS GUARANTEE SHALL BE GOVERNED BY AND
CONSTRUED AND INTERPRETED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK.


            [The remainder of this page left blank intentionally; The
                            signature page follows.]




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<PAGE>


         IN WITNESS WHEREOF, this Guarantee is executed as of the day and year
first above written.

                                  ASSOCIATED BANC-CORP,
                                  as Guarantor

                                  By:
                                     -----------------------------------
                                  Name:
                                  Title:



                                  BNY MIDWEST TRUST COMPANY,
                                  as Guarantee Trustee

                                  By:
                                     -----------------------------------
                                  Name:
                                  Title:



                                       17