FIRST SUPPLEMENTAL INDENTURE between POPULAR, INC. and THE BANK OF NEW YORK MELLON

Exhibit 4.3

EXECUTED VERSION

FIRST SUPPLEMENTAL INDENTURE

between

POPULAR, INC.

and

THE BANK OF NEW YORK MELLON

Dated as of August 24, 2009

T ABLE OF C ONTENTS

F IRST S UPPLEMENTAL I NDENTURE , dated as of August 24, 2009 (the “ First Supplemental Indenture ”), between P OPULAR , I NC . , a Puerto Rico corporation (hereinafter sometimes called the “ Company ”), and T HE B ANK OF N EW Y ORK M ELLON , a New York banking corporation, as trustee (hereinafter sometimes called the “ Trustee ”) under the Indenture dated as of August 24, 2009 between the Company and the Trustee (the “ Indenture ”).

W HEREAS , the Company executed and delivered the Indenture to the Trustee to provide for the future issuance of the Company’s unsecured junior subordinated debentures to be issued from time to time in one or more series as might be determined by the Company under the Indenture, in an unlimited aggregate principal amount which may be authenticated and delivered as provided in the Indenture;

W HEREAS , pursuant to the terms of the Indenture, the Company desires to provide for the establishment of a new series of such securities to be known as its Fixed Rate Perpetual Junior Subordinated Debentures, Series A (the “ Debentures ”), the form and substance of such Debentures and the terms, provisions and conditions thereof to be set forth as provided in the Indenture and this First Supplemental Indenture;

W HEREAS , the Company and Popular Capital Trust III, a Delaware statutory trust (the “ Trust ”), propose to exchange for outstanding Fixed Rate Cumulative Perpetual Preferred Stock, Series C, $1,000 liquidation preference per share, of the Company (the “ Series C Preferred Stock ”) $935,000,000 aggregate liquidation amount of the Trust’s Fixed Rate Capital Securities (the “ Capital Securities ”), representing preferred undivided beneficial interests in the assets of the Trust, and the Trust proposes to use the Series C Preferred Stock, together with the proceeds of the issuance and sale by the Trust to the Company of $1,000,000 aggregate liquidation amount of its Fixed Rate Common Securities (the “ Common Securities ”), to purchase $936,000,000 aggregate principal amount of the Debentures; and

W HEREAS , the Company has requested that the Trustee execute and deliver this First Supplemental Indenture and all requirements necessary to make this First Supplemental Indenture a valid instrument in accordance with its terms, and to make the Debentures, when executed by the Company, and authenticated and delivered by the Trustee, the valid obligations of the Company, have been performed, and the execution and delivery of this First Supplemental Indenture has been duly authorized in all respects.

N OW T HEREFORE , in consideration of the purchase and acceptance of the Debentures by the Holders thereof, and for the purpose of setting forth, as provided in the Indenture, the form and substance of the Debentures and the terms, provisions and conditions thereof, the Company covenants and agrees with the Trustee as follows:

ARTICLE I

D EFINITIONS

Section 1.1 Definition of Terms.

Unless the context otherwise requires:

(a) a term defined in the Indenture has the same meaning when used in this First Supplemental Indenture;

(b) a term defined anywhere in this First Supplemental Indenture has the same meaning throughout;

(c) the singular includes the plural and vice versa;

(d) a reference to a Section or Article is to a Section or Article of this First Supplemental Indenture;

(e) headings are for convenience of reference only and do not affect interpretation;

(f) the following terms have the meanings given to them in the Declaration: (i) Capital Securities Certificate; (ii) Delaware Trustee; (iii) Distributions; (iv) Exchange Agreement; (v) Guarantee; (vi) Property Trustee; and (vii) Trust Securities; and

(g) the following terms have the meanings given to them in this Section 1.1(g):

“ Appropriate Federal Banking Agency ” means the “appropriate Federal banking agency” with respect to the Company as defined in Section 3(q) of the Federal Deposit Insurance Act (12 U.S.C. Section 1813(q)), or any successor provision.

“ Common Stock ” means the common stock, par value $0.01 per share, of the Company.

“ Compound Interest ” shall have the meaning set forth in Section 4.1.

“ Coupon Rate ” shall have the meaning set forth in Section 2.5(a).

“ Creditor ” shall have the meaning set forth in Section 5.1.

“ Declaration ” means the Amended and Restated Declaration of Trust and Trust Agreement of Popular Capital Trust III, a Delaware statutory trust, dated as of August 24, 2009.

“ Deferred Interest ” shall have the meaning set forth in Section 4.1.

“ Dissolution Event ” means the dissolution of the Trust and distribution of the Debentures held by the Property Trustee pro rata to the holders of the Trust Securities in liquidation of such holders’ interests in the Trust in accordance with the Declaration, such event to occur at the option of the Company at any time upon the terms and conditions set forth in the Declaration.

“ Extended Interest Payment Period ” shall have the meaning set forth in Section 4.1.

“ Global Debenture ” shall have the meaning set forth in Section 2.4(a).

“ Holder ” means any person in whose name at the time a Debenture is registered on the Security Register.

“ Interest Payment Date ” shall have the meaning set forth in Section 2.5(a).

“ Interest Period ” means the period beginning on (and including) the date of issue and ending on (but excluding) the first Interest Payment Date and each successive period beginning on (and including) the Interest Payment Date and ending on (but excluding) the next succeeding Interest Payment Date.

“ Non Book-Entry Capital Securities ” shall have the meaning set forth in Section 2.4(a).

“ Redemption Price ” shall have the meaning set forth in Section 3.1.

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“ Special Redemption Event ” means a Tax Event, Investment Company Event or a Capital Treatment Event, as the case may be.

ARTICLE II

G ENERAL T ERMS AND C ONDITIONS OF THE D EBENTURES

Section 2.1 Designation and Principal Amount.

There is hereby authorized a series of Debt Securities designated as the “Fixed Rate Perpetual Junior Subordinated Debentures, Series A”, in aggregate principal amount of $936,000,000.

Section 2.2 No Maturity.

The Debentures shall be perpetual, but shall be redeemable as provided in Article III and subject to acceleration as provided in Article V of the Indenture.

Section 2.3 Form and Payment.

Except as provided in Section 2.4, the Debentures shall be issued in fully registered certificated form without interest coupons. Principal and 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 Trustee in New York, New York; provided, however, that payment of interest may be made at the option of the Company by check mailed to the Holder entitled thereto at such address as shall appear in the Security Register or by wire transfer to an account appropriately designated by the Holder entitled thereto. Notwithstanding the foregoing, so long as the Holder of any Debentures is the Property Trustee, the payment of the principal of and interest (including Compound Interest and Additional Interest, if any) on such Debentures held by the Property Trustee will be made at such place and to such account as may be designated by the Property Trustee.

Section 2.4 Global Debenture.

(a) In connection with a Dissolution Event,

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

(c) Except as otherwise provided in or pursuant to this First Supplemental Indenture, a Global Debenture shall be exchangeable for Debentures in definitive registered form only if (i) the Depositary notifies the Company that it is unwilling or unable to continue as Depositary and a successor Depositary is not appointed by the Company within 90 days of the date the Company is so informed in writing or becomes aware of such condition, (ii) the Depository ceases to be registered as a “clearing agency” under the Securities Exchange Act of 1934, as amended, (iii) an Event of Default, as defined in the Indenture, has occurred and is continuing with respect to the Debentures, or (iv) the Company, in its sole discretion determines that the Debentures shall no longer be represented by such Global Debenture. Upon the occurrence of any of (i) through (iv) above, the Company shall execute, and, subject to Article II of the Indenture, the Trustee, upon written notice from the Company, shall authenticate and deliver the Debentures in definitive registered form without coupons, in authorized denominations, and in an aggregate principal amount equal to the principal amount of the Global Debenture in exchange for such Global Debenture. In the event the Company determines that the Debentures shall no longer be represented by a Global Debenture pursuant to clause (iv) above, the Company shall execute, and, subject to Section 3.05 of the Indenture, the Trustee, upon receipt of an Officers’ Certificate evidencing such determination by the Company, shall authenticate and deliver the Debentures in definitive registered form without coupons, in authorized denominations, and in an aggregate principal amount equal to the principal amount of the Global Debenture in exchange for such Global Debenture. Upon the exchange of the Global Debenture for such Debentures in definitive registered form without coupons, in authorized denominations, the Global Debenture shall be canceled by the Trustee. Such Debentures in definitive registered form issued in exchange for the Global Debenture shall be registered in such names and in such authorized denominations as the Depositary, pursuant to instructions from its direct or indirect participants or otherwise, shall instruct the Trustee. The Trustee shall deliver such Debt Securities to the Depositary for delivery to the Persons in whose names such Debt Securities are so registered.

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Section 2.5 Interest.

(a) Each Debenture will bear interest at a rate of (A) 5.00% per annum for the period from and including August 24, 2009 to but excluding December 5, 2013 and (B) 9.00% per annum thereafter (the “ Coupon Rate ”) until the principal thereof is paid or made available for payment, and to the extent that payment of such interest is enforceable under applicable law, on any overdue installment of interest at the applicable Coupon Rate, compounded quarterly, payable quarterly in arrears on each February 15, May 15, August 15 and November 15 (each, an “ Interest Payment Date ”), commencing on November 15, 2009, to the Person in whose name such Debenture or any predecessor Debenture is registered at the close of business on the relevant record date, which will be, as long as the Capital Securities are in book-entry form (or if no Capital Securities remain outstanding, as long as the Debentures remain in book-entry form), one Business Day prior to the relevant Interest Payment Date and, in the event the Capital Securities are not in book-entry form (or if no Capital Securities remain outstanding, in the event the Debentures are not in book-entry form), the last day of the month next preceding each Interest Payment Date, except as otherwise provided pursuant to the provisions of Article IV.

(b) The amount of interest payable for any period less than a full quarterly 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 quarterly interest period shall be computed by dividing the applicable rate per annum by four. In the event that any date on which interest is payable on the Debentures is not a Business Day, then payment of interest payable on such date will be made on the next succeeding day which is a Business Day (and without any interest or other payment in respect of any such delay).

Section 2.6 Forms of Declaration and Guarantee Agreement.

The Declaration shall be substantially in the form set forth in Exhibit B and the Guarantee Agreement shall be substantially in the form set forth in Exhibit C.

Section 2.7 Events of Default

The Event of Default described in Section 5.01(4) of the Indenture shall not apply to the Debentures.

ARTICLE III

R EDEMPTION OF THE D EBENTURES

Section 3.1 Optional Redemption.

The Debentures are redeemable at the option of the Company at any time (including upon the occurrence and during the continuation of any Special Redemption Event), subject to the approval of the Appropriate Federal Banking Agency, at a redemption price (the “ Redemption Price ”) equal to 100% of the principal amount thereof, plus accrued and unpaid interest thereon (including Compound Interest, if any) to the date of redemption.

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Section 3.2 Redemption Procedures.

Notice of any redemption will be mailed at least 30 days but not more than 60 days before the redemption date to each Holder of Debentures to be prepaid at its registered address. Unless the Company defaults in payment of the Redemption Price, on and after the redemption date interest shall cease to accrue on such Debentures called for redemption. If the Debentures are only partially redeemed pursuant to Section 3.1, the Debentures will be redeemed pro rata or by lot or by any other method utilized by the Trustee; provided that if at the time of redemption the Debentures are registered as a Global Debenture, the Depositary shall determine, in accordance with its procedures, the principal amount of such Debentures held by each Depositary participant to be redeemed. The Redemption Price shall be paid prior to 12:00 noon, New York time, on the date of such redemption or at such earlier time as the Company determines; provided that the Company shall deposit with the Trustee an amount sufficient to pay the Redemption Price by 10:00 a.m., New York time, on the date such Redemption Price is to be paid.

Section 3.3 No Sinking Fund.

The Debentures are not entitled to the benefit of any sinking fund.

ARTICLE IV

E XTENSION OF I NTEREST P AYMENT P ERIOD

This Article IV and the provisions set forth in the form of Debenture, but not the provisions of Section 3.13 of the Indenture, shall apply to the deferral of interest on the Debentures:

Section 4.1 Extension of Interest Payment Period.

Provided that no Event of Default has occurred and is continuing, the Company shall have the right, at any time and from time to time during the term of the Debentures, to defer payments of interest by extending the interest payment period of such Debentures for a period not exceeding 20 consecutive quarterly periods (the “ Extended Interest Payment Period ”), during which Extended Interest Payment Period no interest shall be due and payable. To the extent permitted by applicable law, interest, the payment of which has been deferred because of the extension of the interest payment period pursuant to this Section 4.1, will bear interest thereon at the Coupon Rate compounded quarterly for each quarter of the Extended Interest Payment Period (“ Compound Interest ”). At the end of the Extended Interest Payment Period, the Company shall pay all interest accrued and unpaid on the Debentures, including any Compound Interest (together, “ Deferred Interest ”) that shall be payable to the Holders in whose names the Debentures are registered in the Security Register on the record date for the first Interest Payment Date after the end of the Extended Interest Payment Period. Before the termination of any Extended Interest Payment Period, the Company may further extend such period, provided that such period together with all such previous or further extensions thereof shall not exceed 20 consecutive quarterly periods. Upon the termination of any Extended Interest Payment Period and upon the payment of all Deferred Interest then due, the Company may commence a new Extended Interest Payment Period, subject to the foregoing requirements. No interest shall be due and payable during an Extended Interest Payment Period, except at the end thereof,