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                                                                    EXHIBIT 4.14
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                          REGIONS FINANCIAL CORPORATION

                                       AND

                              BANKERS TRUST COMPANY

                                   as Trustee

               --------------------------------------------------


                          FIRST SUPPLEMENTAL INDENTURE

                          DATED AS OF FEBRUARY 26, 2001


               --------------------------------------------------

              Supplement to Indenture dated as of February 26, 2001
                         (Subordinated Debt Securities)

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                          FIRST SUPPLEMENTAL INDENTURE

         FIRST SUPPLEMENTAL INDENTURE, dated as of February 26, 2001 by and
between REGIONS FINANCIAL CORPORATION., a Delaware corporation (hereinafter
called the "Company"), and BANKERS TRUST COMPANY, a New York banking corporation
(hereafter called the "Trustee"), having a Corporate Trust Office at 4 Albany
Street, 4th Floor, New York, New York, 10006, as Trustee under the Indenture (as
hereinafter defined).

                                    RECITALS

         WHEREAS, the Company and the Trustee have as of February 26, 2001
entered into an Indenture, (hereinafter called the "Indenture") providing for
the issuance by the Company from time to time of its subordinated debt
securities;

         WHEREAS, the Company desires to issue a series of junior subordinated
debt deferrable interest securities under the Indenture, and has duly authorized
the creation and issuance of such debt securities and the execution and delivery
of this First Supplemental Indenture to modify the Indenture and provide certain
additional provisions as hereinafter described;

         WHEREAS, the Company and the Trustee deem it advisable to enter into
this First Supplemental Indenture for the purposes of establishing the terms of
such debt securities and providing for the rights, obligations and duties of the
Trustee with respect to such debt securities;

         WHEREAS, the execution and delivery of this First Supplemental
Indenture has been authorized by a resolution of the Board of Directors of the
Company;

         WHEREAS, concurrent with the execution hereof, the Company has
delivered an Officers' Certificate and has caused its counsel to deliver to the
Trustee an Opinion of Counsel; and

         WHEREAS, all conditions and requirements of the Indenture necessary to
make this First Supplemental Indenture a valid, binding and legal instrument in
accordance with its terms have been performed and fulfilled by the parties
hereto and the execution and delivery thereof have been in all respects duly
authorized by the parties hereto.

         NOW, THEREFORE, THIS FIRST SUPPLEMENTAL INDENTURE WITNESSETH:

         For and in consideration of the mutual premises and agreements herein
contained, the Company and the Trustee covenant and agree, for the equal and
proportionate benefit of all Holders of the Debentures, as follows:


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                                   ARTICLE ONE

                              CREATION OF THE NOTES

         SECTION 1.1.      DESIGNATION OF SERIES. Pursuant to the terms hereof
and Sections 201 and 301 of the Indenture, the Company hereby creates a series
of its debt securities designated as the "8.00% Junior Subordinated Deferrable
Interest Debentures due 2031" (the "Debentures"), which Debentures shall be
deemed "Securities" for all purposes under the Indenture.

         SECTION 1.2.      FORM AND DENOMINATION OF DEBENTURES. The definitive
form of the Debentures shall be substantially in the form set forth in Exhibit A
attached hereto, which is incorporated herein and made part hereof. The
Debentures shall bear interest, be payable and have such other terms as are
stated in the form of definitive Debenture or in the Indenture, as supplemented
by this First Supplemental Indenture. The Stated Maturity of the Debentures
shall be February 28, 2031. The Debentures shall be issued in denominations of
$25 and integral multiples thereof.

         SECTION 1.3.      LIMIT ON AMOUNT OF SERIES. The Debentures shall not
exceed U.S.$296,392,000 in aggregate principal amount, and may, upon the
execution and delivery of this First Supplemental Indenture or from time to time
thereafter, be executed by the Company and delivered to the Trustee for
authentication, and the Trustee shall thereupon authenticate and deliver said
Debentures to or upon the delivery of a Company Order.

         SECTION 1.4.      NO SINKING FUND. No sinking fund will be provided
with respect to the Debentures.

         SECTION 1.5.      DEBENTURES NOT CONVERTIBLE OR EXCHANGEABLE. The
Debentures will not be convertible or exchangeable for other securities or
property.

         SECTION 1.6.      FORM. Except as provided in Section 1.7, the
Debentures shall be issued in fully registered certificated form without
interest coupons. Principal of, premium, if any, and interest (including any
Additional Interest) on the Debentures issued in certificated form will be
payable, the transfer of such Debentures will be registrable and such Debentures
will be exchangeable for Debentures bearing identical terms and provisions at
the office or agency of the Company maintained for such purpose as set forth in
the Indenture.

         SECTION 1.7       GLOBAL DEBENTURE.

         (a)      In connection with a Dissolution Event,

                  (i)      the Debentures in certificated form may be presented
         to the Trustee by the Property Trustee in exchange for a global
         Debenture in an aggregate principal amount equal to the aggregate
         principal amount of all outstanding Debentures (a "Global


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         Debenture"), to be registered in the name of the Depository, or its
         nominee, and delivered by the Trustee to or upon the order of the
         Depository for crediting to the accounts of its participants pursuant
         to the instructions of the Administrative Trustees. The Company upon
         any such presentation shall execute a Global Debenture in such
         aggregate principal amount and deliver the same to the Trustee for
         authentication and delivery in accordance with the Indenture. Payments
         on the Debentures issued as a Global Debenture will be made to the
         Depository; and

                  (ii)     if any Preferred Securities are held in non book-
         entry certificated form, the Debentures in certificated form may be
         presented to the Trustee by the Property Trustee and any certificate
         which represents Preferred Securities (each a "Preferred Security
         Certificate") other than Preferred Securities held by the Clearing
         Agency or its nominee ("Non Book-Entry Preferred Securities") will be
         deemed to represent beneficial interests in Debentures presented to the
         Trustee by the Property Trustee having an aggregate principal amount
         equal to the aggregate liquidation amount of the Non Book-Entry
         Preferred Securities until such Preferred Security Certificates are
         presented to the Security Registrar for transfer or reissuance at which
         time such Preferred Security Certificates will be cancelled and a
         Debenture, registered in the name of the holder of the Preferred
         Security Certificate, or the transferee of the holder of such Preferred
         Security Certificate, as the case may be, with an aggregate principal
         amount equal to the aggregate liquidation amount of the Preferred
         Security Certificate cancelled, will be executed by the Company and
         delivered to the Trustee for authentication and delivery in accordance
         with the Indenture. Upon the issuance of such Debentures, Debentures
         with an equivalent aggregate principal amount that were presented by
         the Property Trustee to the Trustee will be deemed to have been
         cancelled.

         (b)      A Global Debenture may be transferred, in whole but not in
part, only to another nominee of the Depository, or to a successor Depository
selected or approved by the Company or to a nominee of such successor
Depository.

         (c)      For purposes hereof, "Dissolution Event" means the liquidation
of the Regions Financing Trust I (the "Trust") pursuant to the Trust Agreement
relating to the Trust and the distribution of the Debentures held by the
Property Trustee to the Holders of the Trust Securities issued by the Trust pro
rata in accordance with such Trust Agreement.

         SECTION 1.8.      FORM OF TRUST AGREEMENT AND GUARANTEE. Pursuant to
Section 301(25) of the Indenture, so long as any of the Debentures are
Outstanding, the form of Trust Agreement shall be substantially that as set
forth in Exhibit B and the form of Regions Guarantee shall be substantially that
as set forth in Exhibit C.

         SECTION 1.9.      DESIGNATION OF DEPOSITORY. DTC shall act as the
Depository for the Debentures.


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         SECTION 1.10.     DEFEASANCE NOT APPLICABLE TO DEBENTURES. Defeasance
under Section 1402 of the Indenture and covenant defeasance under Section 1403
of the Indenture shall not apply to the Debentures.

                                   ARTICLE TWO

                    APPOINTMENT OF THE TRUSTEE FOR THE NOTES

         SECTION 2.1.      APPOINTMENT OF TRUSTEE. Pursuant and subject to the
Indenture, the Company and the Trustee hereby constitute the Trustee as trustee
to act on behalf of the Holders of the Debentures, and as the principal Paying
Agent and Security Registrar for the Debentures, effective upon execution and
delivery of this First Supplemental Indenture. By execution, acknowledgment and
delivery of this First Supplemental Indenture, the Trustee hereby accepts
appointment as trustee, Paying Agent and Security Registrar with respect to the
Debentures, and agrees to perform such trusts upon the terms and conditions in
the Indenture and in this First Supplemental Indenture set forth.

         SECTION 2.2.      RIGHTS, POWERS, DUTIES AND OBLIGATIONS OF THE
TRUSTEE. Any rights, powers, duties and obligations by any provisions of the
Indenture conferred or imposed upon the Trustee shall, insofar as permitted by
law, be conferred or imposed upon and exercised or performed by the Trustee with
respect to the Debentures.

         SECTION 2.3.      RIGHTS IN INDENTURE APPLICABLE TO TRUSTEE. Bankers
Trust Company, in its capacity as Trustee shall be afforded all of the rights,
powers, immunities and indemnities of the Trustee as set forth in the Indenture
as if such rights, powers, immunities and indemnities were specifically set
forth herein.

                                  ARTICLE THREE

                               REDEMPTION OF NOTES

         Pursuant to Section 301(6) and Section 1101 of the Indenture, so long
as any of the Debentures are Outstanding, the following provisions shall be
applicable to the Debentures:

         SECTION 3.1.      Optional Redemption by the Company. At any time on or
after February 26, 2006, and prior to Stated Maturity, the Debentures may be
redeemed at the option of the Company (an "Optional Redemption"), in whole or in
part, upon notice as set forth in Section 1104 of the Indenture, at a Redemption
Price equal to 100% of the principal amount thereof, together with accrued
interest (including any Additional Interest and/or Additional Sums) to the
Redemption Date.


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         SECTION 3.2.      APPLICABILITY OF ARTICLE. Redemption of the
Debentures at the election of the Company or otherwise, as permitted or required
by any provision of the Debentures or this First Supplemental Indenture, shall
be made in accordance with such provision, Article Eleven of the Indenture and
this Article Three.

         SECTION 3.3.      ADDITIONAL REDEMPTION. The Company may also redeem
the Debentures at any time upon the circumstances as set forth in Section 1108
of the Indenture.

                                  ARTICLE FOUR

                       DEFERRAL OF INTEREST PAYMENT DATES

                  PURSUANT TO SECTION 301(25) OF THE INDENTURE AND IN
         SUBSTITUTION OF THE TERMS OF SECTION 311 OF THE INDENTURE, SO LONG AS
         ANY OF THE NOTES ARE OUTSTANDING, THE FOLLOWING PROVISIONS SHALL BE
         APPLICABLE TO THE NOTES:

         SECTION 4.1.      DEFERRALS OF INTEREST PAYMENT DATES.

         (a)      So long as no Event of Default has occurred and is continuing,
the Company shall have the right, at any time during the term of such series,
from time to time to defer the payment of interest on the Debentures by
extending the interest payment period of such Debentures for a period not
exceeding 20 consecutive quarterly periods (an "Extension Period"). During any
such Extension Period, the Company shall have the right to make partial payments
of interest on any Interest Payment Date. No Extension Period shall end on a
date other than an Interest Payment Date. At the end of any such Extension
Period the Company shall pay all interest then accrued and unpaid on the
Securities (including any Additional Interest and/or any Additional Sums);
provided, however, that no Extension Period shall extend beyond the Stated
Maturity of the Debentures

         (b)      During any Extension Period, the Company shall not (i) declare
or pay any dividends or distributions on, or redeem, purchase, acquire or make a
liquidation payment with respect to, any of the Company's capital stock, or (ii)
make any payment of principal of or interest or premium, if any, on or repay,
repurchase or redeem any debt security of the Company that ranks pari passu with
or junior in interest to the Debentures in all respects or make any guarantee
payments with respect to any guarantee by the Company of the debt securities or
preferred securities of any Subsidiary of the Company that by their terms rank
pari passu with or junior in interest to the Debentures in all respects,
provided, the Company may make such payments on or in respect of any other
series of the Company's debt securities and any such guarantees ranking equally
with the Debentures or any Regions Guarantee relating thereto on a pro rata
basis so that the payments made on such debt securities or such guarantees and
the Debentures and such Regions Guarantee in all cases bear to each other the
same ratio that accrued and unpaid payments on such debt securities and such
guarantees and the Debentures and such Regions


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Guarantee bear to each other (other than, in each case, (A) repurchases,
redemptions or other acquisitions of shares of capital stock of the Company in
connection with any employment contract, benefit plan or other similar
arrangement with or for the benefit of one or more employees, officers,
directors or consultants, in connection with a dividend reinvestment or
stockholder stock purchase plan, in connection with the issuance of capital
stock of the Company (or securities convertible into or exercisable for such
capital stock) as consideration in an acquisition transaction entered into prior
to any applicable Extension Period or in connection with transactions effected
by or for the account of customers of the Company or any Affiliate of the
Company or in connection with the distribution, trading or market-making in
respect of the Preferred Securities, (B) as a result of any exchange or
conversion of any class or series of the Company's capital stock (or any capital
stock of a Subsidiary of the Company) for any class or series of the Company's
capital stock or of any class or series of the Company's indebtedness for any
class or series of the Company's capital stock, (C) the purchase of fractional
interests in shares of the Company's capital stock pursuant to the conversion or
exchange provisions of such capital stock or the security being converted or
exchanged, (D) any declaration of a dividend in connection with any
stockholder's rights plan, or the issuance of rights, stock or other property
under any stockholder's rights plan, or the redemption or repurchase of rights
pursuant thereto, or (E) any dividend in the form of stock, warrants, options or
other rights where the dividend stock or the stock issuable upon exercise of
such warrants, options or other rights is the same stock as that on which the
dividend is being paid or ranks pari passu with or junior to such stock). Prior
to the termination of any such Extension Period, the Company may further defer
the payment of interest, provided that no Extension Period shall exceed the
period or periods specified in such Securities or extend beyond the Stated
Maturity hereof. Upon termination of any Extension Period and upon the payment
of all accrued and unpaid interest and any Additional Interest or Additional
Sums then due on any Interest Payment Date, the Company may elect to begin a new
Extension Period, subject to the above requirements. No interest shall be due
and payable during an Extension Period, except at the end thereof, but each
installment of interest that would otherwise have been due and payable during
such Extension Period shall bear interest at the interest rate then in effect
compounded quarterly for each quarterly period of the extension period
("Additional Interest"). The Company shall give the Trustee prior written notice
of its election to begin any such Extension Period at least one Business Day
prior to the earlier of (1) the next succeeding date on which Distributions on
the Preferred Securities of the applicable Regions Trust would be payable but
for such deferral, and (2) the date on which the Property Trustee of the
applicable Regions Trust is required to give notice to any securities exchange
or other applicable self-regulatory organization or to holders of such Preferred
Securities of the record date or the date such Distributions are payable.

                                  ARTICLE FIVE

                              ADDITIONAL COVENANTS


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         Pursuant to Section 301(15)(b) of the Indenture and in substitution of
the terms of Section 1014 of the Indenture, so long as any of the Notes are
Outstanding, the following provisions shall be applicable to the Notes:

         SECTION 5.1.      ADDITIONAL COVENANTS.

         (a)      The Company covenants and agrees with each Holder of
Securities of each series that it shall not (i) declare or pay any dividends or
distributions on, or redeem, purchase, acquire or make a liquidation payment
with respect to, any of the Company's capital stock, or (ii) make any payment of
principal of or interest or premium, if any, on or repay, repurchase or redeem
any debt security of the Company that ranks pari passu with or junior in
interest in to the Debentures in all respects or make any guarantee payments
with respect to any guarantee by the Company of the debt securities or preferred
securities of any Subsidiary of the Company that by their terms rank pari passu
with or junior in interest to the Debentures in all respects, provided, the
Company may make such payments on or in respect of any other series of it debt
securities and any such guarantees ranking equally with the Debentures or any
Regions Guarantee relating thereto on a pro rata basis so that the payments made
on such debt securities or such guarantees and the Debentures and such Regions
Guarantee in all cases bear to each other the same ratio that accrued and unpaid
payments on such debt securities and such guarantees and the Debentures and such
Regions Guarantee bear to each other (other than, in each case, (A) repurchases,
redemptions or other acquisitions of shares of capital stock of the Company in
connection with any employment contract, benefit plan or other similar
arrangement with or for the benefit of one or more employees, officers,
directors or consultants, in connection with a dividend reinvestment or
stockholder stock purchase plan, in connection with the issuance of capital
stock of the Company (or securities convertible into or exercisable for such
capital stock) as consideration in an acquisition transaction entered into prior
to any applicable Extension Period or in connection with transactions effected
by or for the account of customers of the Company or any Affiliate of the
Company or in connection with the distribution, trading or market-making in
respect of the Preferred Securities, (B) as a result of any exchange or
conversion of any class or series of the Company's capital stock (or any capital
stock of a Subsidiary of the Company) for any class or series of the Company's
capital stock or of any class or series of the Company's indebtedness for any
class or series of the Company's capital stock, (C) the purchase of fractional
interests in shares of the Company's capital stock pursuant to the conversion or
exchange provisions of such capital stock or the security being converted or
exchanged, (D) any declaration of a dividend in connection with any
stockholder's rights plan, or the issuance of rights, stock or other property
under any stockholder's rights plan, or the redemption or repurchase of rights
pursuant thereto, or (E) any dividend in the form of stock, warrants, options or
other rights where the dividend stock or the stock issuable upon exercise of
such warrants, options or other rights is the same stock as that on which the
dividend is being paid or ranks pari passu with or junior to such stock), if at
such time (1) there shall have occurred any event of which the Company has
actual knowledge that (x) with the giving of notice or the lapse of time or
both, would constitute an Event of Default with respect to the


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Securities of such series and (y) in respect of which the Company shall not have
taken reasonable steps to cure, (2) if the Securities of such series are held by
a Regions Trust, the Company shall be in default with respect to its payment of
any obligations under the Regions Guarantee relating to the Preferred Securities
issued by such Regions Trust, or (3) the Company shall have given written notice
of its election to begin an Extension Period with respect to the Securities of
such series as provided herein and shall not have rescinded such notice, or such
Extension Period, or any extension thereof, shall be continuing.

         (b)      The Company also covenants with each Holder of Securities of a
series issued to a Regions Trust (i) to maintain directly or indirectly 100%
ownership of the Common Securities of such Regions Trust; provided, however,
that any permitted successor of the Company hereunder may succeed to the
Company's ownership of such Common Securities, (ii) as holder of such Common
Securities, not to voluntarily terminate, wind-up or liquidate such Trust, other
than (a) in connection with a distribution of the Securities of such series to
the holders of the related Preferred Securities in liquidation of such Trust, or
(b) in connection with certain mergers, consolidations or amalgamations
permitted by the related Trust Agreement, and (iii) to use its reasonable
efforts, consistent with the terms and provisions of such Trust Agreement, to
cause such Regions Trust to remain classified as a grantor trust and not an
association taxable as a corporation for United States federal income tax
purposes.

                                   ARTICLE SIX

                                 LEGAL HOLIDAYS

         Pursuant to Section 201 and Section 301(15)(b) of the Indenture and in
substitution of the terms of Section 113 of the Indenture, so long as any of the
Notes are Outstanding, the following provisions shall be applicable to the
Notes:

         SECTION 6.1       LEGAL HOLIDAYS. In any case where any Interest
Payment Date, Redemption Date, Stated Maturity or Maturity of any Note shall not
be a Business Day at any Place of Payment, then payment of interest or any
Additional Amounts or principal (and premium, if any) need not be made at such
Place of Payment on such date, or exchange need not be made at such Place of
Payment on such date, but may be made on the next succeeding Business Day at
such Place of Payment, or if such Business Day falls in the next calendar month,
on the immediately preceding Business Day, with the same force and effect as if
made on the Interest Payment Date, Redemption Date or at the Stated Maturity or
Maturity, provided that so long as such payment is made on the next succeeding
Business Day, no interest shall accrue on the amount so payable for the period
from and after such Interest Payment Date, Redemption Date, Stated Maturity or
Maturity, to such Business Day.


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                                  ARTICLE SEVEN

                                  MISCELLANEOUS

         SECTION 7.1.      APPLICATION OF FIRST SUPPLEMENTAL INDENTURE. Each and
every term and condition contained in the First Supplemental Indenture that
modifies, amends or supplements the terms and conditions of the Indenture shall
apply only to the Debentures created hereby and not to any future series of
Debentures established under the Indenture.

         SECTION 7.2.      BENEFITS OF FIRST SUPPLEMENTAL INDENTURE. Nothing
contained in this First Supplemental Indenture shall or shall be construed to
confer upon any person other than a Holder of the Debentures, the Company and
the Trustee any right or interest to avail itself or himself, as the case may
be, of any benefit under any provision of the Indenture or this First
Supplemental Indenture, except for Holders of Senior Debt as provided in Article
Seventeen of the Indenture.

         SECTION 7.3.      DEFINED TERMS. All capitalized terms which are used
herein and not otherwise defined herein are defined in the Indenture and are
used herein with the same meanings as in the Indenture.

         SECTION 7.4.      EFFECTIVE DATE. This First Supplemental Indenture
shall be effective as of the date first above written and upon the execution and
delivery hereof by each of the parties hereto.

         SECTION 7.5.      GOVERNING LAW. This First Supplemental Indenture
shall be governed by, and construed in accordance with, the laws of the State of
New York.

         SECTION 7.6.      COUNTERPARTS. This First Supplemental Indenture may
be executed in any number of counterparts, each of which so executed shall be
deemed to be an original, but all such counterparts shall together constitute
but one and the same instrument.

         SECTION 7.7.      SATISFACTION AND DISCHARGE. This First Supplemental
Indenture shall cease to be of further force and effect upon compliance with
such provisions of Article Fourteen of the Indenture as may be applicable to the
Debentures pursuant to Article Three hereof with respect to the Debentures
created hereby.

                            [SIGNATURES ON NEXT PAGE]


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         IN WITNESS WHEREOF, the parties hereto have caused this First
Supplemental Indenture to be duly executed by their respective officers hereunto
duly authorized, all as of the day and year first above written.

                              REGIONS FINANCIAL CORPORATION



                              By:  /s/ Samuel E. Upchurch, Jr.
                                 -----------------------------------------------
                              Name:  Samuel E. Upchurch, Jr.
                              Title: Executive Vice President, General Counsel
                                     and Corporate Secretary



                              BANKERS TRUST COMPANY
                                 as Trustee



                              By: /s/ Eileen M. Hughes
                                 -----------------------------------------------
                              Name:  Eileen M. Hughes
                              Title: Vice President


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<PAGE>   12

                    EXHIBIT A TO FIRST SUPPLEMENTAL INDENTURE

                                FORM OF DEBENTURE

[THE FOLLOWING LEGEND SHALL APPEAR ON THE FACE OF EACH GLOBAL SECURITY:

         THIS NOTE IS A SECURITY IN GLOBAL FORM ("GLOBAL SECURITY") WITHIN THE
MEANING OF THE SECTION 203 OF THE BASE INDENTURE HEREINAFTER REFERRED TO AND IS
REGISTERED IN THE NAME OF THE DEPOSITORY OR A NOMINEE OF THE DEPOSITORY, WHICH
MAY BE TREATED BY THE COMPANY, THE TRUSTEE AND ANY AGENT THEREOF AS OWNER AND
HOLDER OF THIS NOTE FOR ALL PURPOSES.

         UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF
THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE COMPANY OR
ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE
ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS
REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO
CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER
HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

         UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN
DEFINITIVE REGISTERED FORM IN THE LIMITED CIRCUMSTANCES REFERRED TO IN THE
INDENTURE, THIS GLOBAL SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE
DEPOSITORY TO A NOMINEE OF THE DEPOSITORY OR BY A NOMINEE OF THE DEPOSITORY TO
THE DEPOSITORY OR ANOTHER NOMINEE OF THE DEPOSITORY OR BY THE DEPOSITORY OR ANY
SUCH NOMINEE TO A SUCCESSOR DEPOSITORY OR A NOMINEE OF SUCH SUCCESSOR
DEPOSITORY.]


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                          REGIONS FINANCIAL CORPORATION

             8.00% JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURE
                                    DUE 2031

No. ________________                                       U.S.$ _______________

CUSIP NO. ___________________

         REGIONS FINANCIAL CORPORATION, a corporation duly organized and
existing under the laws of the State of Delaware (herein called the "Company",
which term includes any successor Person under the Indenture referred to on the
reverse hereof), for value received, hereby promises to pay to
________________________, the principal sum of ________ United States Dollars
(U.S.$______ ) (which principal amount may from time to time be increased or
decreased to such other principal amounts (which, taken together with the
principal amounts of all other Outstanding Debentures under this Series of
Debentures, shall not exceed U.S.$296,392,000 in the aggregate at any time, all
of which shall be represented hereby) by adjustments made on the records of the
Trustee hereinafter referred to in accordance with the Indenture) on February
28, 2031 and to pay interest thereon, from February 26, 2001, or from the most
recent Interest Payment Date (as defined below) to which interest has been paid
or duly provided for, quarterly (subject to deferral as set forth herein) in
arrears on March 31, June 30, September 30 and December 31 in each year (each,
an "Interest Payment Date"), commencing June 30, 2001, at the rate of 8.00% per
annum, until the principal hereof is due, and at the rate of 8.00% per annum on
any overdue principal and premium, if any, and, to the extent permitted by law,
on any overdue interest. The interest so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in the Indenture,
be paid to the Person in whose name this Debenture (or one or more Predecessor
Securities) is registered at the close of business on the Regular Record Date
for such interest, which shall be the March 15, June 15, September 15 or
December 15 (whether or not a Business Day), as the case may be, next preceding
such Interest Payment Date. Except as otherwise provided in the Indenture, any
such interest not so punctually paid or duly provided for will forthwith cease
to be payable to the Holder on such Regular Record Date and may either be paid
to the Person in whose name this Debenture (or one or more Predecessor
Securities) is registered at the close of business on a Special Record Date for
the payment of such Defaulted Interest to be fixed by the Trustee, notice
whereof shall be given to Holders of Debentures not less than 10 days prior to
the Special Record Date, or be paid at any time in any other lawful manner not
inconsistent with the requirements of any automated quotation system or
securities exchange on which the Debentures may be quoted or listed, and upon
such notice as may be required by such exchange, all as more fully provided in
the Indenture. Payments of principal shall be made upon the surrender of this
Debenture at the Corporate Trust Office of the Trustee, or at such other office
or agency of the Company as may be designated by the COMPANY for such purpose in
the Borough of Manhattan, The City of New York or in the City of Birmingham,
Alabama, in such coin or currency of the United States of America as at the time
of payment shall be legal tender for the payment of public and private debts, by
Dollar check drawn on, or transfer to, a Dollar account. Payments of interest on
this


                                      A-2
<PAGE>   14

Debenture may be made by Dollar check, drawn on a Dollar account, mailed to the
address of the Person entitled thereto as such address shall appear in the
Security Register, or, upon written application by the Holder to the Security
Registrar setting forth wire instructions not later than the relevant Record
Date, by transfer to a Dollar account.

         The indebtedness evidenced by this Debenture is, to the extent and in
the manner provided in the Indenture, subordinate and subject in right of
payment to the prior payment in full in cash of all Senior Debt of the Company,
and this Debenture is issued subject to such provisions of the Indenture with
respect thereto. Each Holder of this Debenture, by accepting the same, (a)
agrees to and shall be bound by such provisions, (b) authorizes and directs the
Trustee on his behalf to take such action as may be necessary or appropriate to
effectuate the subordination so provided and (c) appoints the Trustee his
attorney-in-fact for any and all such purposes.

         THIS DEBENTURE IS NOT A SAVINGS ACCOUNT DEPOSIT OR OTHER OBLIGATION OF
A BANK OR NONBANK SUBSIDIARY THEREOF, AND IS NOT INSURED BY THE FEDERAL DEPOSIT
INSURANCE CORPORATION, THE BANK INSURANCE FUND OR ANY OTHER GOVERNMENTAL AGENCY.

         Except as specifically provided herein and in the Indenture, the
Company shall not be required to make any payment with respect to any tax,
assessment or other governmental charge imposed by any government or any
political subdivision or taxing authority thereof or therein.

         Reference is hereby made to the further provisions of this Debenture
set forth on the reverse hereof, which further provisions shall for all purposes
have the same effect as if set forth at this place.

         Unless the certificate of authentication hereon has been executed by
the Trustee referred to on the reverse hereof or an Authenticating Agent by the
manual signature of one of their respective authorized signatories, this
Debenture shall not be entitled to any benefit under the Indenture or be valid
or obligatory for any purpose.


                                      A-3
<PAGE>   15

         IN WITNESS WHEREOF, the Company has caused this Debenture to be duly
executed and delivered under its corporate seal.

                                  REGIONS FINANCIAL CORPORATION
[Corporate Seal]


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

Attest:


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


                                      A-4
<PAGE>   16

                    (Trustee's Certificate of Authentication)

         This is one of the Securities of the series designated therein referred
to in the within-mentioned Indenture.


                                BANKERS TRUST COMPANY, as Trustee


                                By:
                                   ---------------------------------------------
                                   Authorized Officer


                                      A-5
<PAGE>   17

                                [FORM OF REVERSE]

         This Debenture is one of a duly authorized issue of securities of the
Company designated as its "8.00% Junior Subordinated Deferrable Interest
Debentures due 2031" (herein called the "Debentures"), limited in aggregate
principal amount to U.S. $296,392,000, issued and to be issued under an
Indenture, dated as of February 26, 2001 (herein called the "Base Indenture"),
between the Company and Bankers Trust Company, as Trustee (herein called the
"Trustee", which term includes any successor trustee under the Base Indenture),
and a First Supplemental Indenture, dated as of February 26, 2001 between the
Company and the Trustee (the "First Supplemental Indenture"; the Base Indenture,
as supplemented by the First Supplemental Indenture, the "Indenture") to which
Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities
thereunder of the Company, the Trustee, the holders of Senior Debt and the
Holders of the Debentures and of the terms upon which the Debentures are, and
are to be, authenticated and delivered. As provided in the Indenture and subject
to certain limitations therein set forth, Debentures are exchangeable for a like
aggregate principal amount of Debentures of any authorized denominations as
requested by the Holder surrendering the same upon surrender of the Debenture or
Debentures to be exchanged, at the Corporate Trust Office of the Trustee. The
Trustee upon such surrender by the Holder will issue the new Debentures in the
requested denominations.

         No sinking fund is provided for the Debentures.

         Upon the occurrence and continuation of a Tax Event, Investment Company
Event or Capital Treatment Event, the Company shall have the right, subject to
certain conditions set forth in the Indenture, to redeem this Debenture in
whole, but not in part, at the Redemption Price within 90 days following the
occurrence of such Tax Event, Investment Company Event or Capital Treatment
Event (or, if the prior approval of the Board of Governors of the Federal
Reserve System (the "Federal Reserve") is then required, on such later date as
promptly and practicable after such approval is obtained). In addition, the
Debentures are subject to redemption at the option of the Company at any time on
or after February 26, 2006, in whole or in part, upon not less than 30 nor more
than 60 days' notice to the Holders prior to the Redemption Date at a Redemption
Price equal to 100% of the principal amount thereof, together with accrued and
unpaid interest (including any Additional Interest and/or Additional Sums) to
the Redemption Date; provided, however, that interest installments on Debentures
whose Stated Maturity is on or prior to such Redemption Date will be payable to
the Holders of such Debentures, or one or more Predecessor Securities, of record
at the close of business on the relevant Record Dates referred to on the face
hereof, all as provided in the Indenture. Notwithstanding the foregoing, any
redemption of Debentures by the Company shall be subject to the prior approval
of the Federal Reserve, if such approval is then required under applicable law,
rules, guidelines or policies of the Federal Reserve.

         In the event of a redemption of the Debentures, the Company will not be
required (a) to register the transfer or exchange of Debentures for a period of
15 days immediately preceding the date notice is given identifying the serial
numbers of the Debentures called for such


                                      A-6
<PAGE>   18

redemption or (b) to register the transfer or exchange of any Debenture, or
portion thereof, called for redemption.

         In any case where the due date for the payment of the principal of,
premium, if any, or interest on any Debenture at any Place of Payment as the
case may be, a day on which banking institutions at such Place of Payment are
authorized or obligated by law or executive order to close, then payment of
principal, premium, if any, or interest (including any Additional Interest
and/or Additional Sums) need not be made on or by such date at such place but
may be made on or by the next succeeding day at such place which is not a day on
which banking institutions are authorized or obligated by law or executive order
to close, with the same force and effect as if made on the date for such payment
or the date fixed for redemption, and no interest shall accrue on the amount so
payable for the period after such date; provided if such next succeeding day
falls in the next calendar month, such payment shall be payable on the first day
preceding the date on which such payment was otherwise due which is not a day on
which banking institutions are authorized or obligated by law or executive order
to close.

         [The following paragraph shall appear in each Global Security:

         In the event of a deposit or withdrawal of an interest in this
Debenture, including an exchange, transfer, redemption or repayment of this
Debenture in part only, the Trustee, as custodian of the Depository, shall make
an adjustment on its records to reflect such deposit or withdrawal in accordance
with the rules and procedures of The Depository Trust Company applicable to, and
as in effect at the time of, such transaction.]

         [The following paragraph shall appear in each Debenture that is not a
Global Security:

         In the event of redemption or repayment of this Debenture in part only,
a new Debenture or Debentures for the unredeemed portion hereof will be issued
in the name of the Holder hereof.]

         If an Event of Default shall occur and be continuing, the principal of
all the Debentures, together with accrued interest to the date of declaration,
may be declared due and payable in the manner and with the effect provided in
the Indenture. Upon payment (i) of the amount of principal so declared due and
payable, together with accrued interest to the date of declaration, and (ii) of
interest on any overdue principal and, to the extent permitted by applicable
law, overdue interest, all of the Company's obligations in respect of the
payment of the principal of and interest on the Debentures shall terminate.

         The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Debentures under the Indenture at
any time by the Company and the Trustee with the written consent of the Holders
of not less than a majority in principal amount of the Debentures at the time
Outstanding. The Indenture also contains provisions permitting the Holders of
specified percentages in principal amount of the Debentures at the time
Outstanding, on behalf of the Holders of all the Debentures, to waive compliance
by the Company with


                                      A-7
<PAGE>   19

certain provisions of the Indenture and certain past defaults under the
Indenture and their consequences. Any such consent or waiver by the Holder of
this Debenture shall be conclusive and binding upon such Holder and upon all
future Holders of this Debenture and of any Debenture issued in exchange herefor
or in lieu hereof whether or not notation of such consent or waiver is made upon
this Debenture or such other Debenture.

         As provided in and subject to the provisions of the Indenture, the
Holder of this Debenture shall not have the right to institute any proceeding
with respect to the Indenture or for the appointment of a receiver or trustee or
for any other remedy thereunder, unless such Holder shall have previously given
the Trustee written notice of a continuing Event of Default, the Holders of not
less than 25% in principal amount of the Outstanding Debentures shall have made
written request to the Trustee to institute proceedings in respect of such Event
of Default as Trustee and offered the Trustee reasonable indemnity and the
Trustee shall not have received from the Holders of a majority in principal
amount of the Outstanding Debentures a direction inconsistent with such request,
and shall have failed to institute any such proceeding, for 60 days after
receipt of such notice, request and offer of indemnity. The foregoing shall not
apply to any suit instituted by the Holder of this Debenture for the enforcement
of any payment of principal hereof, premiums if any, or interest hereon on or
after the respective due dates expressed herein or for the enforcement of the
right to convert this Debenture as provided in the Indenture.

         So long as no Event of Default has occurred and is continuing, the
Company shall have the right, at any time during the term of such series, from
time to time to defer the payment of interest on the Debentures by extending the
interest payment period of this Debenture for a period not exceeding 20
consecutive quarterly periods (an "Extension Period"). During any such Extension
Period the Company shall have the right to make partial payments of interest on
any Interest Payment Date. No Extension Period shall end on a date other than an
Interest Payment Date. At the end of any such Extension Period the Company shall
pay all interest then accrued and unpaid on the Securities (including any
Additional Interest and any Additional Sums); provided, however, that no
Extension Period shall extend beyond the Stated Maturity hereof; provided,
further, that during any such Extension Period, the Company shall not (i)
declare or pay any dividends or distributions on, or redeem, purchase, acquire
or make a liquidation payment with respect to, any of the Company's capital
stock, or (ii) make any payment of principal of or interest or premium, if any,
on or repay, repurchase or redeem any debt security of the Company that ranks
pari passu with or junior in interest to the Debentures in all respects or make
any guarantee payments with respect to any guarantee by the Company of the debt
securities or preferred securities of any Subsidiary of the Company that by
their terms rank pari passu with or junior in interest to the Debentures in all
respects, provided, the Company may make such payments on or in respect of any
other series of the Company's debt securities and any such guarantees ranking
equally with the Debentures or any Regions Guarantee relating thereto on a pro
rata basis so that the payments made on such debt securities or such guarantees
and the Debentures and such Regions Guarantee in all cases bear to each other
the same ratio that accrued and unpaid payments on such debt securities and such
guarantees and the Debentures and such Regions Guarantee bear to each other
(other than, in each case, (a) repurchases, redemptions or other acquisitions of
shares of capital stock of the Company in connection with any employment
contract, benefit plan or other similar arrangement with or for


                                      A-8
<PAGE>   20

the benefit of one or more employees, officers, directors or consultants, in
connection with a dividend reinvestment or stockholder stock purchase plan, in
connection with the issuance of capital stock of the Company (or securities
convertible into or exercisable for such capital stock) as consideration in an
acquisition transaction entered into prior to any applicable Extension Period or
in connection with transactions effected by or for the account of customers of
the Company or any Affiliate of the Company or in connection with the
distribution, trading or market-making in respect of the Preferred Securities,
(b) as a result of any exchange or conversion of any class or series of the
Company's capital stock (or any capital stock of a Subsidiary of the Company)
for any class or series of the Company's capital stock or of any class or series
of the Company's indebtedness for any class or series of the Company's capital
stock, (c) the purchase of fractional interests in shares of the Company's
capital stock pursuant to the conversion or exchange provisions of such capital
stock or the security being converted or exchanged, (d) any declaration of a
dividend in connection with any stockholder's rights plan, or the issuance of
rights, stock or other property under any stockholder's rights plan, or the
redemption or repurchase of rights pursuant thereto, or (e) any dividend in the
form of stock, warrants, options or other rights where the dividend stock or the
stock issuable upon exercise of such warrants, options or other rights is the
same stock as that on which the dividend is being paid or ranks pari passu with
or junior to such stock). Prior to the termination of any such Extension Period,
the Company may further defer the payment of interest, provided that no
Extension Period shall exceed the period or periods specified in such Securities
or extend beyond the Stated Maturity hereof. Upon termination of any Extension
Period and upon the payment of all accrued and unpaid interest and any
Additional Interest or Additional Sums then due on any Interest Payment Date,
the Company may elect to begin a new Extension Period, subject to the above
requirements. No interest shall be due and payable during an Extension Period,
except at the end thereof, but each installment of interest that would otherwise
have been due and payable during such Extension Period shall bear interest at
the interest rate then in effect compounded quarterly for each quarterly period
of the extension period ("Additional Interest"). The Company shall give the
Trustee prior written notice of its election to begin any such Extension Period
at least one Business Day prior to the earlier of (i) the next succeeding date
on which Distributions on the Preferred Securities of the applicable Regions
Trust would be payable but for such deferral, and (ii) the date on which the
Property Trustee of the applicable Regions Trust is required to give notice to
any securities exchange or other applicable self-regulatory organization or to
holders of such Preferred Securities of the record date or the date such
Distributions are payable.

         The Trustee, at the expense of the Company, shall promptly give notice
of the Company's election to begin any such Extension Period to the Holder.

         No reference herein to the Indenture and no provision of this Debenture
or of the Indenture shall alter or impair the obligation of the Company, which
is absolute and unconditional, to pay the principal of, premium, if any, and
interest (including any Additional Interest or Additional Sums) on this
Debenture at the times, places and rate, and in the coin or currency, herein
prescribed.


                                      A-9
<PAGE>   21

         As provided in the Indenture and subject to certain limitations therein
set forth, the transfer of this Debenture is registrable on the Security
Register upon surrender of this Debenture for registration of transfer at the
Corporate Trust Office of the Trustee or at such other office or agency of the
Company as may be designated by it for such purpose in the Borough of Manhattan,
The City of New York or the City of Birmingham, Alabama (which shall initially
be an office or agency of the Trustee), or at such other offices or agencies as
the Company may designate, duly endorsed by, or accompanied by a written
instrument of transfer in form satisfactory to the Company and the Security
Registrar duly executed by, the Holder thereof or his attorney duly authorized
in writing, and thereupon one or more new Debentures, of authorized
denominations and for the same aggregate principal amount, will be issued to the
designated transferee or transferees by the Registrar. No service charge shall
be made for any such registration of transfer or exchange, but the Company may
require payment of a sum sufficient to recover any tax or other governmental
charge payable in connection therewith.

         Prior to due presentation of this Debenture for registration of
transfer, the Company, the Trustee and any agent of the Company or the Trustee
may treat the Person in whose name this Debenture is registered, as the owner
thereof for all purposes, whether or not such Debenture be overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the
contrary.

         No recourse for the payment of the principal (and premium, if any) or
interest (including any Additional Interest) or Additional Sums on this
Debenture and no recourse under or upon any obligation, covenant or agreement of
the Company in the Indenture or any indenture supplemental thereto or in any
Debenture, or because of the creation of any indebtedness represented thereby,
shall be had against any incorporator, stockholder, employee, agent, officer or
director or subsidiary, as such, past, present or future, of the Company or of
any successor corporation, either directly or through the Company or any
successor corporation, whether by virtue of any constitution, statute or rule of
law or by the enforcement of any assessment or penalty or otherwise, all such
liability being, by the acceptance hereof and as part of consideration for the
issue hereof, expressly waived and released.

         THE INDENTURE AND THIS DEBENTURE SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, UNITED STATES OF AMERICA.

         All capitalized terms used in this Debenture which are defined in the
Indenture shall have the meanings assigned to them in the Indenture.


                                      A-10
<PAGE>   22

         (1)

                               (2) ABBREVIATIONS

         The following abbreviations, when used in the inscription of the face
of this Debenture, shall be construed as though they were written out in full
according to applicable laws or regulations:

<TABLE>
         <S>                        <C>     <C>
         (3)      TEN COM           -       AS TENANTS IN COMMON

         TEN ENT                    -       as tenants by the entireties (Cust)
         JT TEN                     -       as joint tenants with right of survivorship
                                            and not as tenants in common
         UNIF GIFT MIN ACT          -       _________________ Custodian _____________
                                                                   (Minor)
                                            under Uniform Gifts to Minors Act_____________
                                                            (State)
</TABLE>

     Additional abbreviations may also be used though not in the above list.


                                      A-11
<PAGE>   23

                             (b) FORM OF ASSIGNMENT

         For value received ________________ hereby sell(s), assign(s) and
transfer(s) unto ________________ (Please insert social security or other
identifying number of assignee) the within Debenture, and hereby irrevocably
constitutes and appoints ____________________ as attorney to transfer the said
Debenture on the books of the Company, with full power of substitution in the
premises.


Dated:


------------------------            ----------------------

------------------------            ----------------------


                                       Signature(s)

                                       Signature(s) must be guaranteed by
                                       an Eligible Guarantor Institution with
                                       membership in an approved signature
                                       guarantee program pursuant to Rule 17Ad-
                                       15 under the Securities Exchange Act of
                                       1934.


                                      A-12
<PAGE>   24

                    EXHIBIT B TO FIRST SUPPLEMENTAL INDENTURE

                             FORM OF TRUST AGREEMENT


                                       B-1
<PAGE>   25


                    EXHIBIT C TO FIRST SUPPLEMENTAL INDENTURE

                            FORM OF REGIONS GUARANTEE


                                       C-1