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                                                                    EXHIBIT 4(Q)


                                 TRUST AGREEMENT

         THIS TRUST AGREEMENT is made as of January 7, 2002, by and between
Compass Bancshares, Inc., an Alabama banking corporation, as Depositor (the
"Depositor"), and Chase Manhattan Bank USA, National Association, duly organized
and existing under the laws of the United States of America, as Trustee (the
"Trustee").

         The Depositor and the Trustee hereby agree as follows:

         Section 1. THE TRUST. The trust created hereby shall be known as
"Compass Trust III" (the "Trust"), in which name the Trustee, or the Depositor
to the extent provided herein, may conduct the business of the Trust, make and
execute contracts, and sue and be sued.

         Section 2. THE TRUST ESTATE. The Depositor hereby assigns, transfers,
conveys and sets over the Trustee the sum of Ten and No/100 Dollars ($10.00).
The Trustee hereby acknowledges receipt of such amount in trust from the
Depositor, which amount shall constitute the initial trust estate. The Trustee
hereby declares that it will hold the trust estate in trust for the Depositor.
It is the intention of the parties hereto that the Trust created hereby
constitute a business trust under Chapter 38 of Title 12 of the Delaware Code,
12 Del. C. ss. 3801 et seq. (the "Business Trust Act"), and that this document
constitute the governing instrument of the Trust. The Trustee is hereby
authorized and directed to execute and file a certificate of trust with the
Delaware Secretary of State substantially in the form attached hereto or in such
other form as the Trustee may approve.

         Section 3. AMENDED AND RESTATED TRUST AGREEMENT. The Depositor, the
Trustee and certain other parties will enter into an amended and restated Trust
Agreement, satisfactory to each such party and substantially in the form to be
included as an exhibit to the Registration Statement on Form S-3 (the "1933 Act
Registration Statement") referred to below or in such other form as the Trustee
and the Depositor may approve, to provide for the contemplated operation of the
Trust created hereby and the issuance of the Preferred Securities and Common
Securities referred to therein. Prior to the execution and delivery of such
amended and restated Trust Agreement, the Trustee shall not have any duty or
obligation hereunder or with respect to the trust estate.

         Section 4. CERTAIN AUTHORIZATIONS. The Depositor and the Trustee hereby
authorize and direct the Depositor, as the sponsor of the Trust, (i) to file
with the Securities and Exchange Commission (the "Commission") and execute, in
each case on behalf of the Trust (a) the 1933 Act Registration Statement,
including any pre-effective or post-effective amendments to such 1933 Act
Registration Statement relating to the registration under the Securities Act of
1933, as amended (the "1933 Act"), of the Preferred Securities of the Trust and
certain other securities of the Depositor, (b) any preliminary prospectus or
prospectus summary or supplement thereto relating to the Preferred Securities
required to be filed pursuant to Rule 424 under the 1933 Act and (c) a
Registration Statement on Form 8-A (the "1934 Act Registration Statement")
(including all pre-effective and post-effective amendments thereto) relating to
the registration of


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the Preferred Securities of the Trust under Section 12 of the Securities
Exchange Act of 1934, as amended; (ii) to file with one or more national
securities exchanges (each, an "Exchange") or the National Association of
Securities Dealers ("NASD") and execute on behalf of the Trust a listing
application or applications and all other applications, statements,
certificates, agreements and other instruments as shall be necessary or
desirable to cause the Preferred Securities to be listed on any such Exchange or
the NASD's Nasdaq National Market ("NASDAQ"); (iii) to file and execute on
behalf of the Trust such applications, reports, surety bonds, irrevocable
consents, appointments of attorney for service of process and other papers and
documents as the Depositor, on behalf of the Trust, may deem necessary or
desirable to register the Preferred Securities under the state securities or
"Blue Sky" laws; and (iv) to execute on behalf of the Trust such other
underwriting agreements with one or more underwriters relating to the offering
of the Preferred Securities as the Depositor, on behalf of the Trust, may deem
necessary or desirable. In the event that any filing referred to in clauses (i),
(ii), or (iii) above is required by the rules and regulations of the Commission,
any Exchange, the NASD or state securities or "Blue Sky" laws, to be executed on
behalf of the Trust by a Trustee, the Depositor and any Trustee appointed
pursuant to Section 6 hereof are hereby authorized to join in any such filing
and to execute on behalf of the Trust by a Trustee, the Depositor and any
Trustee appointed pursuant to Section 6 hereof are hereby authorized to join in
any such filing and to execute on behalf of the Trust any and all of the
foregoing.

         Section 5. COUNTERPARTS. This Trust Agreement may be executed in one or
more counterparts, each of which shall be deemed an original but all of which
together shall constitute one and the same instrument.

         Section 6. TRUSTEES. The number of Trustees initially shall be one (1)
and thereafter the number of Trustees shall be such number as shall be fixed
from time to time by written instrument signed by the Depositor, which may
increase or decrease the number of Trustees; provided, however, that to the
extent required by the Business Trust Act, one Trustee shall either be a natural
person who is a resident of the State of Delaware, or, if not a natural person,
an entity which has its principal place of business in the State of Delaware and
otherwise meets the requirement of applicable Delaware law. Subject to the
foregoing, the Depositor is entitled to appoint or remove without cause any
Trustee at any time. The Trustee may resign upon thirty (30) days' prior notice
to the Depositor.

         Section 7. GOVERNING LAW. This Trust Agreement shall be governed by,
and construed in accordance with, the laws of the State of Delaware (without
regard to conflicts of law principles).

         Section 8. LIABILITY. The Trustee and its successors and assigns (the
"Fiduciary Indemnified Persons") shall not be liable, responsible or accountable
in damages or otherwise to the Trust, the Depositor, the Trustees or any holder
of the Trust's securities (the Trust, the Depositor and any holder of the
Trust's securities being a "Covered Person") for any loss, damage or claim
incurred by reason of any act or omission performed or omitted by the Fiduciary
Indemnified Persons in good faith on behalf of the Trust and in a manner the
Fiduciary Indemnified Persons reasonably believed to be within the scope of
authority conferred on the Fiduciary Indemnified Persons by this Trust Agreement
or by law, except that the Fiduciary


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Indemnified Persons shall be liable for any such loss, damage or claim incurred
by reason of the Fiduciary Indemnified Person's gross negligence or willful
misconduct with respect to such acts or omissions.

                  The Fiduciary Indemnified Persons shall be fully protected in
relying in good faith upon the records of the Trust and upon such information,
opinions, reports or statements presented to the Trust by any person as to
matters the Fiduciary Indemnified Persons reasonably believes are within such
other person's professional or expert competence and who has been selected with
reasonable care by or on behalf of the Trust, including information, opinions,
reports or statements as to the value and amount of the assets, liabilities,
profits, losses or any other facts pertinent to the existence and amount of
assets from which distributions to holders of Trust's securities might properly
be paid.

         Section 9. INDEMNIFICATION. The Depositor agrees, to the fullest extent
permitted by applicable law, to indemnify and hold harmless each Fiduciary
Indemnified Person, or any of its officers, directors, shareholders, employees,
representatives or agents, from and against any loss, damage, liability, tax,
penalty, expense or claim of any kind or nature whatsoever incurred by the
Fiduciary Indemnified Persons by reason of the creation, operation or
termination of the Trust in a manner the Fiduciary Indemnified Persons
reasonably believed to be within the scope of authority conferred on the
Fiduciary Indemnified Persons by this Trust Agreement, except that no Fiduciary
Indemnified Persons shall be entitled to be indemnified in respect of any loss,
damage or claim incurred by the Fiduciary Indemnified Persons by reason of gross
negligence or willful misconduct with respect to such acts or omissions. In case
any such claim, demand, action, suit or proceeding shall be brought involving a
Fiduciary Indemnified Person, the Fiduciary Indemnified Person shall promptly
notify the Depositor of such claim, demand, action, suit or proceeding and the
Depositor shall assume the defense thereof, including the employment of counsel
reasonably satisfactory to such Fiduciary Indemnified Person and the payment of
all expenses. The Fiduciary Indemnified Person shall have the right to employ
separate counsel in any such claim, demand, action, suit or proceeding and to
participate in the defense thereof, but the reasonable counsel fees and expenses
of such counsel shall not be paid by the Depositor unless (i) the employment of
counsel by such Fiduciary Indemnified Person has been expressly authorized in
writing by the Depositor, (ii) such Fiduciary Indemnified Person shall have
reasonably concluded that there exists a conflict of interest between such
Fiduciary Indemnified Person and the Depositor in the conduct of the defense of
such action (in which case the Depositor shall not have the right to direct the
defense of such action on behalf of such Fiduciary Indemnified Person) or (iii)
the Depositor shall not in fact have employed counsel reasonably satisfactory to
the Fiduciary Indemnified Person to assume the defense of such action, in each
of which cases the reasonable fees and expenses of counsel used by such
Fiduciary Indemnified Person shall be paid by the Depositor.

                  The provisions of this Section shall survive the termination
of this Trust Agreement or the earlier resignation or removal of the Fiduciary
Indemnified Persons.


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         IN WITNESS WHEREOF, the parties hereto have caused this Trust Agreement
to be duly executed as of the day and year first above written.


                                  COMPASS BANCSHARES, INC.
                                           As Depositor


                                  By:      /s/ D. Paul Jones, Jr.
                                  ----------------------------------------------
                                           Name:    D. Paul Jones, Jr.
                                           Title:   Chairman and Chief Executive
                                                    Officer



                                  CHASE MANHATTAN BANK USA,
                                  NATIONAL ASSOCIATION,
                                           As Trustee


                                  By:      /s/ John J. Cashin
                                  ----------------------------------------------
                                           Name:    John J. Cashin
                                           Title:   Vice President







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