AGL CAPITAL CORPORATION 5.25% SENIOR SECURED NOTES

Exhibit 4.1

This Security is a global security within the meaning of the Indenture hereinafter referred to and is registered in the name of a depositary (as defined in the Indenture) or a nominee thereof. This global security is exchangeable for securities registered in the name of a person other than the depositary or its nominee only in the limited circumstances described in the Indenture and, unless and until it is exchanged in whole or in part for securities in definitive form, this global 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 depositary or a nominee of such successor depositary.

Unless this security is presented by an authorized representative of the Depository Trust Company, a New York corporation (“DTC”), to AGL Capital Corporation (the “Company”) or its agent for registration of transfer exchange, or payment, and any security 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.

AGL CAPITAL CORPORATION

5.25% Senior Notes due 2019

Guaranteed by

AGL Resources Inc.

AGL Capital Corporation, a corporation organized and existing under the laws of the State of Nevada (herein called the “Company,” which terms includes any successor corporation under the Indenture referred to hereinafter), for value received, hereby promises to pay to Cede & Co., as the nominee of The Depository Trust Company, or registered assigns, the principal sum of Three Hundred Million and 00/100 Dollars and to pay interest thereon from August 15, 2009 semi-annually on each Interest Payment Date of February 15th and August 15th of each year, commencing on February 15, 2010 at 5.25% per annum, until the principal hereof is paid or provided for. Interest so payable shall be computed on the basis of a 360-day year consisting of twelve 30-day months. The interest so payable, and paid or duly provided for, on any Interest Payment Date shall, as provided in such Indenture, be paid to the Person in whose name this Security is registered at the close of business on the Regular Record Date for such interest, which shall be January 1 and July 1 (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 paid or duly provided for shall 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 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 for this series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture.

Payment of the principal of and premium, if any, on this Security at Stated Maturity shall be paid by wire transfer in immediately available funds (except that payment on certificated notes shall be paid by check except in certain circumstances) upon presentation hereof at the offices of The Bank of New York Mellon Trust Company, N.A. or at such other office or agency as may be designated for such purpose by the Company from time to time. Payment of interest on this Security shall be made by wire transfer in immediately available funds (except that payment on certificated notes shall be paid by check except in certain circumstances) to the Person entitled thereto as indicated in the Security Register. Payment of the principal of and premium, if any, and interest on this Security, as aforesaid, shall be made 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.

This Security is one of a duly authorized issue of securities of the Company (herein called the “Securities”), issued and issuable in one or more series under an Indenture, dated as of February 20, 2001 (such Indenture as originally executed and delivered and as supplemented or modified, together with any constituent instruments establishing the terms of particular

Securities, being herein called the “Indenture”), between the Company, AGL Resources Inc. and The Bank of New York Mellon Trust Company, N.A., as successor to The Bank of New York (herein called the “Trustee,” which term includes any successor trustee under the Indenture), to which Indenture, all indentures supplemental thereto or Officer’s Certificates pursuant to Section 301 of such Indenture 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. The acceptance of this Security shall be deemed to constitute the consent and agreement by the Holder hereof to all of the terms and provisions of the Indenture.

If any Interest Payment Date or the Stated Maturity shall not be a Business Day, payment of the amounts due on this Security on such date may be made on the next succeeding Business Day, as if each such payment were made on the date such payment were due and no interest shall accrue on such amounts for the period from and after such Interest Payment Date, or Stated Maturity, as the case may be, to such Business Day.

If an Event of Default with respect to Securities of this series shall occur and be continuing, the principal of this Security 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 exce