<PAGE>
                                                                     EXHIBIT 4.2

                               [FACE OF DEBENTURE]


         The following legend applies if this Security is a Global Security:
Unless this certificate is presented by an authorized representative of The
Depository Trust Company, a New York corporation ("DTC"), to the Issuer 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
requested by an authorized representative of DTC (and any payment is made to
Cede & Co. or 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.

         This Security is not a deposit or other obligation of a depository
institution and is not insured by the Federal Deposit Insurance Corporation, the
Bank Insurance Fund or any other governmental agency.

CUSIP NO. __________                             PRINCIPAL AMOUNT: $___________
REGISTERED NO. _____

                                  POPULAR, INC.

                _____% JUNIOR SUBORDINATED DEBENTURES, SERIES ___
                             DUE _____________, 20__

         POPULAR, INC., a corporation duly organized and existing under the laws
of the Commonwealth of Puerto Rico (hereinafter called the "Company," which term
includes any successor corporation under the Indenture hereinafter referred to),
for value received, hereby promises to pay to ______________________________, or
registered assigns, the principal sum of _______________________________________
($____________) on _____________, 20__. The Company further promises to pay
interest on the principal sum from _____________, 2003 or from the most recent
Interest Payment Date to which interest has been paid or duly provided for
monthly (subject to deferral as set forth herein) on the first day of each month
of each year commencing _____________, 2003 at the rate of _____% per annum,
together with Additional Sums, if any, as provided in Section 1007 of the
Indenture, until the principal hereof is paid or made available for payment;
provided, however, that any overdue installment of interest (after giving effect
to any Extension Period permitted by this Security) shall bear Additional
Interest at the rate of _____% per annum (to the extent that the payment of such
interest shall be legally enforceable), compounded monthly, from the date such
installment was due until it is paid or made available for payment. The amount
of interest payable for any period less than a full monthly interest period
shall be computed on the basis of a 360-day year of twelve 30-day months and the
actual days elapsed in a partial month in such period. The amount of interest
payable for any full monthly interest period shall be computed by dividing the
applicable rate per annum by twelve. 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 Security (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 15th calendar day (whether or
not a Business


<PAGE>


Day, as defined below) next preceding such Interest Payment Date. If an Interest
Payment Date is not a Business Day, interest on this Security shall be payable
on the next day that is a Business Day, with the same force and effect as if
made on such Interest Payment Date, and without any interest or other payment
with respect to the delay. "Business Day" as used hereinabove is a day other
than a Saturday, a Sunday or any other day on which banking institutions in San
Juan, Puerto Rico, Wilmington, Delaware or New York, New York are authorized or
required by law, regulation or executive order to remain closed or and
customarily closed.

         Any interest not 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 Security (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 Securities of this series not less than 10
days prior to such Special Record Date, or be paid at any time in any other
lawful manner not inconsistent with the requirements of any securities exchange
on which the Securities of this series may be listed, and upon such notice as
may be required by such exchange, all as more fully 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 this Security, from
time to time to defer the payment of interest on this Security for up to 60
consecutive monthly interest payment periods with respect to each deferral
period (each an "Extension Period"), during which Extension Period the Company
shall have the right to make a partial payment of interest on any Interest
Payment Date, at the end of which the Company shall pay all interest then
accrued and unpaid including any Additional Interest, as provided below;
provided, however, that no Extension Period shall extend beyond the Maturity of
the principal of this Security and no such Extension Period may end other than
at the end of a full monthly interest period; and provided, further, however,
that during any such Extension Period, the Company shall not (i) make any
payment of principal of or interest or premium, if any, on or repay, repurchase
or redeem any debt securities of the Company that rank pari passu in all
respects with or junior in interest to this Security (except for any partial
payments of interest with respect to and permitted under the Securities of this
series), or (ii) 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 (other than (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 any one or more employees, officers, directors, consultants or
independent contractors, in connection with a dividend reinvestment or
stockholder stock purchase plan or 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 the applicable Extension Period, (b) as a result of an exchange, redemption
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 other 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



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capital stock or the security being converted or exchanged, (d) any declaration
of a dividend in connection with any Rights Plan, or the issuance of rights,
stock or other property under any Rights Plan, or the redemption or repurchase
of rights pursuant thereto, (e) payments by the Company under the Guarantee
Agreement, or (f) 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 extend such
Extension Period and further defer the payment of interest, provided that no
Extension Period shall exceed 60 consecutive monthly interest payment periods,
extend beyond the Maturity of the principal of this Security or end other than
at the end of a full monthly interest period. Upon the termination of any such
Extension Period and upon the payment of all accrued and unpaid interest and any
Additional Interest then due on any Interest Payment Date, the Company may elect
to begin a new Extension Period, subject to the above conditions. No interest or
Additional 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 Additional Interest
(to the extent that the payment of such interest shall be legally enforceable)
at the rate of _____% per annum, compounded monthly and calculated as set forth
in the first paragraph of this Security, from the dates on which amounts would
otherwise have been due and payable until paid or made available for payment.
The Company shall give the Holder of this Security and the Trustee notice of its
election to begin any Extension Period at least one Business Day prior to the
next succeeding Interest Payment Date on which interest on this Security would
be payable but for such deferral or, so long as such Securities are held by or
on behalf of Popular Capital Trust __, at least one Business Day prior to the
earlier of (i) the next succeeding date on which Distributions on the Capital
Trust Securities of such Issuer Trust would be payable but for such deferral,
and (ii) the date on which the Property Trustee of such Issuer Trust is required
to give notice to holders of such Capital Trust Securities of the record date or
the date such Distributions are payable.

         Payment of interest, including Additional Interest, on this Security
will be made in immediately available funds at the office or agency of the
Company maintained for that purpose in the City of San Juan, Puerto Rico, in
such coin or currency of the United States of America as at the time of payment
is legal tender for payment of public and private debts; provided, however,
that, at the option of the Company, payment of interest may be paid by check
mailed to the Person entitled thereto at such Person's last address as it
appears in the Security Register or, upon written request of a Holder of
$1,000,000 or more in aggregate principal amount of Securities of this series
not less than 15 calendar days prior to the applicable Interest Payment Date, by
wire transfer to such account as may have been designated by such Person.
Payment of principal of and interest, including Additional Interest, on this
Security at Maturity will be made against presentation of this Security at the
office or agency of the Company maintained for that purpose in the City of San
Juan, Puerto Rico.

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


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         Unless the certificate of authentication hereon has been executed by
the Trustee referred to on the reverse hereof by manual signature or its duly
authorized agent under the Indenture referred to on the reverse hereof by manual
signature, this Security shall not be entitled to any benefit under the
Indenture or be valid or obligatory for any purpose.

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

DATED:
      -------------------------
                                             POPULAR, INC.



                                             By:
                                                --------------------------------

[SEAL]

                                             Attest:
                                                    ----------------------------
                                                            Secretary

TRUSTEE'S CERTIFICATE
OF AUTHENTICATION
This is one of the Securities
of the series designated
therein referred to in the
within-mentioned Indenture.

Bank One Trust Company, N.A.,
as Trustee


By:
   -----------------------------------
          Authorized Signature

OR

________________________________, as
Authenticating Agent for the Trustee



By:
   -----------------------------------
          Authorized Signature



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<PAGE>

                             [REVERSE OF DEBENTURE]


                                  POPULAR, INC.

                _____% JUNIOR SUBORDINATED DEBENTURES, SERIES ___
                             DUE _____________, 20__


         This Security is one of a duly authorized issue of junior subordinated
securities of the Company (herein called the "Securities"), issued and to be
issued in one or more series under an indenture dated as of _____________, 2003,
as amended or supplemented from time to time (herein called the "Indenture"),
between the Company and Bank One Trust Company, N.A., as Trustee (herein called
the "Trustee," which term includes any successor trustee under 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 and the Holders of the
Securities, and of the terms upon which the Securities are, and are to be,
authenticated and delivered. This Security is one of the series designated on
the face hereof, limited in aggregate principal amount to $_______________. All
terms used in this Security which are defined in the Indenture shall have the
meanings assigned to them in the Indenture unless otherwise defined in this
Security.

         Subject to any required prior approval of the Primary Federal
Regulator, the Company may at any time, at its option, on or after
_____________, 20__, and subject to the terms and conditions of Article Eleven
of the Indenture, redeem the Securities of this series in whole at any time or
in part from time to time, at a Redemption Price equal to 100% of the principal
amount thereof, together, in the case of any such redemption, with accrued but
unpaid interest, including any Additional Interest, to but excluding the
Redemption Date.

         In addition, upon the occurrence and during the continuation of a Tax
Event, an Investment Company Event or a Capital Treatment Event in respect of
Popular Capital Trust __, the Company may, at its option, at any time within 90
days of the occurrence and during the continuation of such Tax Event, Investment
Company Event or Capital Treatment Event, as the case may be, subject to any
required prior approval of the Primary Federal Regulator, redeem the Securities
of this series, in whole but not in part, subject to the terms and conditions of
Article Eleven of the Indenture, at a Redemption Price equal to 100% of the
principal amount thereof, together, in the case of any such redemption, with
accrued but unpaid interest, including any Additional Interest, to but excluding
the Redemption Date.

         The Securities of this series are not subject to repayment at the
option of the Holder hereof. The Securities of this series will not be entitled
to any sinking fund.

         The indebtedness evidenced by the Securities of this series is, to the
extent and in the manner set forth in the Indenture, subordinate and subject in
right of payment to the prior payment in full of the principal of and premium,
if any, and interest on all Senior Debt of the Company, and each Holder of the


                                       5
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Securities of this series, by accepting the same, agrees to and shall be bound
by the provisions of the Indenture with respect hereto. The Securities of this
series shall rank on a parity with all Trust Related Securities, including
without limitation, the Guarantee Agreement related to the _____% Capital
Securities of Popular Capital Trust __.

         If an Event of Default, as defined in the Indenture, with respect to
Securities of this series shall occur and be continuing, the principal of the
Securities of this series may be declared due and payable in the manner and with
the effect provided in the Indenture.

         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 Securities of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of a majority in principal amount of the Securities at
the time Outstanding of all series to be affected, acting together. The
Indenture also contains provisions permitting the Holders of a majority in
principal amount of the Securities of all series at the time Outstanding
affected by certain provisions of the Indenture, acting together, on behalf of
the Holders of all Securities of such series, to waive compliance by the Company
with those provisions of the Indenture. Certain past defaults under the
Indenture and their consequences may be waived under the Indenture by the
Holders of a majority in principal amount of the Securities of each series at
the time Outstanding, on behalf of the Holders of all Securities of such series.
All of the rights of the Holders set forth in this paragraph are subject to the
rights of the holders of Capital Trust Securities as set forth in the Indenture.
Any such consent or waiver by the Holder of this Security shall be conclusive
and binding upon such Holder and upon all future Holders of this Security and of
any Security issued upon the registration of transfer hereof or in exchange
herefor or in lieu hereof, whether or not notation of such consent or waiver is
made upon this Security.

         The provisions contained in Section 403 and Article Seventeen of the
Indenture for defeasance of the entire indebtedness on this Security and certain
restrictive covenants and certain Events of Default do not apply to this
Security. The provisions contained in Section 401 of the Indenture for
defeasance of the entire indebtedness on this Security in certain circumstances
shall apply to this Security.

         Upon due presentment for registration of transfer of this Security at
the office or agency of the Company in the City of San Juan, Puerto Rico, a new
Security or Securities of this series in authorized denominations of $___ or
integral multiples thereof for an equal aggregate principal amount will be
issued to the transferee in exchange herefor, as provided in the Indenture and
subject to the limitations provided therein and to the limitations described
below, without charge except for any tax or other governmental charge imposed in
connection therewith.

         If this Security is a Global Security, this Security is exchangeable
for definitive Securities in registered form only if (x) the Depositary notifies
the Company that it is unwilling or unable to continue as Depositary for this


                                       6
<PAGE>

Security or if at any time the Depositary ceases to be a clearing agency
registered under the Securities Exchange Act of 1934, as amended, and a
successor depositary is not appointed within 90 days, (y) the Company in its
sole discretion determines that this Security shall be exchangeable for
definitive Securities in registered form and notifies the Trustee thereof, or
(z) an Event of Default with respect to the Securities represented hereby has
occurred and is continuing. If this Security is exchangeable pursuant to the
preceding sentence, it shall be exchangeable for definitive Securities in
registered form, bearing interest, including Additional Interest, at the same
rate, having the same date of issuance, redemption provisions, Stated Maturity
and other terms and of authorized denominations aggregating a like amount.

         If this Security is a Global Security, this Security may not be
transferred except as a whole by the Depositary to a nominee of the Depositary
or by a nominee of the Depositary to the Depositary or another nominee of the
Depositary or by the Depositary or any such nominee to a successor of the
Depositary or a nominee of such successor. Except as provided above, owners of
beneficial interests in this global Security will not be entitled to receive
physical delivery of Securities in definitive form and will not be considered
the Holders hereof for any purpose under the Indenture.

         Subject to the rights of holders of Senior Debt of the Company set
forth in this Security and the indenture referred to above, no reference herein
to the Indenture and no provision of this Security or of the Indenture shall
alter or impair the obligation of the Company, which is absolute and
unconditional, to pay the principal of and interest, including any Additional
Interest, on this Security at the times, place and rate, and in the coin or
currency, herein prescribed, except as otherwise provided in this Security and
except that in the event the Company deposits money or Eligible Instruments as
provided in Section 401 of the Indenture, such payments will be made only from
proceeds of such money or Eligible Instruments.

         Prior to due presentment of this Security 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 Security is registered as the owner hereof for all
purposes, whether or not this Security be overdue, and neither the Company, the
Trustee nor any such agent shall be affected by notice to the contrary.

         No recourse shall be had for the payment of the principal of or the
interest, including Additional Interest, on this Security, or for any claim
based hereon, or otherwise in respect hereof, or based on or in respect of the
Indenture or any indenture supplemental thereto, against any incorporator,
stockholder, officer or director, as such, past, present or future, of 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 the
consideration for the issuance hereof, expressly waived and released.

         The Company and, by its acceptance of this Security or a beneficial
interest herein, the Holder of, and any Person that acquires a beneficial
interest in, this Security, agree that for United States Federal, Puerto Rico,
state and local tax purposes it is intended that this Security constitute
indebtedness.


                                       7
<PAGE>

                                  ABBREVIATIONS


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

TEN COM  --  as tenants in common

TEN ENT  --  as tenants by the entireties

JT TEN   --  as joint tenants with right of survivorship and not as tenants in
             common

UNIF GIFT MIN ACT --  _______________________ Custodian _______________________
                             (Cust)                             (Minor)


Under Uniform Gifts to Minors Act


---------------------------------
           (State)

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

         FOR VALUE RECEIVED, the undersigned hereby sell(s) and transfer(s) unto

Please Insert Social Security or
Other Identifying Number of Assignee


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


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

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

------------------------------------------------------------------------------
 (Please print or type name and address including postal zip code of Assignee)

the within Security of POPULAR, INC. and does hereby irrevocably constitute and
appoint __________________ attorney to transfer the said Security on the books
of the Company, with full power of substitution in the premises.

Dated:
      ----------------------------


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

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


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<PAGE>

NOTICE: The signature to this assignment must correspond with the name as
written upon the face of the within instrument in every particular, without
alteration or enlargement or any change whatever.




                                       9