DUKE ENERGY CORPORATION TO THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. Trustee

Exhibit 4.1

DUKE ENERGY CORPORATION

TO

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.

Trustee

Third Supplemental Indenture
Dated as of August 28, 2009

$500,000,000 3.95% SENIOR NOTES DUE 2014
$500,000,000 5.05% SENIOR NOTES DUE 2019

TABLE OF CONTENTS ¹

      THIS THIRD SUPPLEMENTAL INDENTURE is made as of the 28th day of August 2009, by and between DUKE ENERGY CORPORATION , a Delaware corporation, having its principal office at 526 South Church Street, Charlotte, North Carolina 28202 (the “Corporation”), and The Bank of New York Mellon Trust Company, N.A. (formerly known as The Bank of New York Trust Company, N.A.), a national banking association, as Trustee (herein called the “Trustee”).

WITNESSETH:

      WHEREAS , the Corporation has heretofore entered into an Indenture, dated as of June 3, 2008 (the “Original Indenture”), with The Bank of New York Mellon Trust Company, N.A., as Trustee;

      WHEREAS , the Original Indenture is incorporated herein by this reference and the Original Indenture, as it may be amended and supplemented to the date hereof, including by this Third Supplemental Indenture, is herein called the “Indenture”;

      WHEREAS , under the Indenture, a new series of Securities may at any time be established in accordance with the provisions of the Indenture and the terms of such series may be described by a supplemental indenture executed by the Corporation and the Trustee;

      WHEREAS , the Corporation hereby proposes to create under the Indenture two additional series of Securities;

      WHEREAS , additional Securities of other series hereafter established, except as may be limited in the Indenture as at the time supplemented and modified, may be issued from time to time pursuant to the Indenture as at the time supplemented and modified; and

      WHEREAS , all conditions necessary to authorize the execution and delivery of this Third Supplemental Indenture and to make it a valid and binding obligation of the Corporation have been done or performed.

      NOW, THEREFORE , in consideration of the agreements and obligations set forth herein and for other good and valuable consideration, the sufficiency of which is hereby acknowledged, the parties hereto hereby agree as follows:

ARTICLE I

3.95% SENIOR NOTES DUE 2014

     Section 1.01. Establishment . There is hereby established a new series of Securities to be issued under the Indenture, to be designated as the Corporation’s 3.95% Senior Notes due 2014 (the “2014 Notes”).

     There are to be authenticated and delivered $500,000,000 principal amount of the 2014 Notes, and no further 2014 Notes shall be authenticated and delivered except as provided by Section 304, 305, 306, 906 or 1106 of the Original Indenture and the last paragraph of Section 301 thereof. The 2014 Notes shall be issued in fully registered form without coupons.

     The 2014 Notes shall be in substantially the form set out in Exhibit A hereto, and the form of the Trustee’s Certificate of Authentication for the 2014 Notes shall be in substantially the form set forth in Exhibit B hereto.

     Each 2014 Note shall be dated the date of authentication thereof and shall bear interest from the date of original issuance thereof or from the most recent Interest Payment Date to which interest has been paid or duly provided for.

     Section 1.02. Definitions . The following defined terms used in this Article 1 shall, unless the context otherwise requires, have the meanings specified below for purposes of the 2014 Notes. Capitalized terms used herein for which no definition is provided herein shall have the meanings set forth in the Original Indenture.

     “Business Day” means any day other than a Saturday or a Sunday, that is neither a Legal Holiday nor a day on which banking institutions in New York, New York are authorized or required by law, regulation or executive order to close or a day on which the Corporate Trust Office is closed for business.

     “Interest Payment Date” means each March 15 and September 15 of each year, commencing March 15, 2010.

     “Legal Holiday” means any day that is a legal holiday in New York, New York.

     “Original Issue Date” means August 28, 2009.

     “Regular Record Date” means, with respect to each Interest Payment Date, the close of business on the 15th calendar day prior to such Interest Payment Date (whether or not a Business Day).

     “Stated Maturity” means September 15, 2014.

     Section 1.03. Payment of Principal and Interest . The principal of the 2014 Notes shall be due at Stated Maturity (unless earlier redeemed). The unpaid principal amount of the 2014 Notes shall bear interest at the rate of 3.95% per annum until paid or duly provided for, such interest to accrue from August 28, 2009 or from the most recent Interest Payment Date to which interest has been paid or duly provided for. Interest shall be paid semi-annually in arrears on each Interest Payment Date to the Person or Persons in whose name the 2014 Notes are registered on the Regular Record Date for such Interest Payment Date; provided that interest payable at the Stated Maturity or on a Redemption Date as provided herein shall be paid to the Person to whom principal is payable. Any such interest that is not so punctually paid or duly provided for shall forthwith cease to be payable to the Holders on such Regular Record Date and may either be paid to the Person or Persons in whose name the 2014 Notes are registered at the close of business on a Special Record Date for the payment of such defaulted interest to be fixed by the Trustee (“Special Record Date”), notice whereof shall be given to Holders of the 2014 Notes not less than ten (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, if any, on

which the 2014 Notes may be listed, and upon such notice as may be required by any such exchange, all as more fully provided in the Original Indenture.

     Payments of interest on the 2014 Notes shall include interest accrued to but excluding the respective Interest Payment Dates. Interest payments for the 2014 Notes shall be computed and paid on the basis of a 360-day year of twelve 30-day months. In the event that any date on which interest is payable on the 2014 Notes is not a Business Day, then payment of the interest payable on such date shall be made on the next succeeding day that is a Business Day (and without any interest or payment in respect of any such delay) with the same force and effect as if made on the date the payment was originally payable.

     Payment of principal of, premium, if any, and interest on the 2014 Notes shall be made 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. Payments of principal of, premium, if any, and interest on 2014 Notes represented by a Global Security shall be made by wire transfer of immediately available funds to the Holder of such Global Security, provided that, in the case of payments of principal and premium, if any, such Global Security is first surrendered to the Paying Agent. If any of the 2014 Notes are no longer represented by a Global Security, (i) payments of principal, premium, if any, and interest due at the Stated Maturity or earlier redemption of such 2014 Notes shall be made at the office of the Paying Agent upon surrender of such 2014 Notes to the Paying Agent and (ii) payments of interest shall be made, at the option of the Corporation, subject to such surrender where applicable, (A) by check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register or (B) by wire transfer at such place and to such account at a banking institution in the United States as may be designated in writing to the Trustee at least sixteen (16) days prior to the date for payment by the Person entitled thereto.

     Section 1.04. Denominations . The 2014 Notes shall be issued in denominations of $2,000 or any integral multiple of $1,000 in excess thereof.

     Section 1.05. Global Securities . The 2014 Notes shall initially be issued in the form of one or more Global Securities registered in the name of the Depositary (which initially shall be The Depository Trust Company) or its nominee. Except under the limited circumstances described below, 2014 Notes represented by such Global Security or Global Securities shall not be exchangeable for, and shall not otherwise be issuable as, 2014 Notes in definitive form. The Global Securities described in this Article 1 may not be transferred except 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 to a successor Depositary or its nominee.

     A Global Security shall be exchangeable for 2014 Notes registered in the names of persons other than the Depositary or its nominee only if (i) the Depositary notifies the Corporation that it is unwilling or unable to continue as a Depositary for such Global Security and no successor Depositary shall have been appointed by the Corporation within 90 days of receipt by the Corporation of such notification, or if at any time the Depositary ceases to be a clearing agency registered under the Exchange Act at a time when the Depositary is required to be so registered to act as such Depositary and no successor Depositary shall have been appointed by the Corporation within 90 days after it becomes aware of such cessation, (ii) an Event of

Default has occurred and is continuing with respect to the 2014 Notes and beneficial owners of a majority in aggregate principal amount of the 2014 Notes represented by Global Securities advise the Depositary to cease acting as Depositary, or (iii) the Corporation in its sole discretion, and subject to the procedures of the Depositary, determines that such Global Security shall be so exchangeable. Any Global Security that is exchangeable pursuant to the preceding sentence shall be exchangeable for 2014 Notes registered in such names as the Depositary shall direct.

     Section 1.06. Redemption . The 2014 Notes shall be redeemable, in whole or from time to time in part, at the option of the Corporation on any date (a “Redemption Date”), at a Redemption Price equal to the greater of (i) 100% of the principal amount of the 2014 Notes to be redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest thereon (exclusive of interest accrued to such Redemption Date) discounted to such Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 25 basis points, plus, in either case, accrued and unpaid interest on the principal amount being redeemed to such Redemption Date.

     “Treasury Rate” means, with respect to any Redemption Date for the 2014 Notes, the rate per annum equal to the semi-annual equivalent yield to maturity or interpolated maturity (on a day count basis) of the applicable Comparable Treasury Issue, assuming a price for such Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the applicable Comparable Treasury Price for such Redemption Date. The Treasury Rate shall be calculated on the third Business Day preceding the Redemption Date.

     “Comparable Treasury Issue” when used in this Section 1.06 means the United States Treasury security selected by the Quotation Agent as having an actual or interpolated maturity comparable to the remaining term of the 2014 Notes to be redeemed that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such 2014 Notes.

     “Quotation Agent” means a Reference Treasury Dealer appointed by the Corporation.

     “Comparable Treasury Price” means, with respect to any Redemption Date for the 2014 Notes, (1) the average of the Reference Treasury Dealer Quotations for such Redemption Date, after excluding the highest and lowest such Reference Treasury Dealer Quotations, or (2) if fewer than four such Reference Treasury Dealer Quotations are obtained, the average of all such Reference Treasury Dealer Quotations.

     “Reference Treasury Dealer” means each of BNY Mellon Capital Markets, LLC, Credit Suisse Securities (USA) LLC, J.P. Morgan Securities Inc. and RBS Securities Inc. plus one other financial institution appointed by the Corporation at the time of any redemption of the 2014 Notes or their respective affiliates which are primary U.S. Government securities dealers in the United States (a “Primary Treasury Dealer”) and their respective successors; provided, however, that if any of the foregoing or their affiliates or successors ceases to be a Primary Treasury Dealer, the Corporation will substitute therefor another Primary Treasury Dealer.

     “Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date for the 2014 Notes, the average, as determined by the

Quotation Agent, of the bid and asked prices for the applicable Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Quotation Agent by such Reference Treasury Dealer at 5:00 p.m., New York City time, on the third Business Day preceding such Redemption Date.

     The Corporation shall notify the Trustee of the Redemption Price with respect to any redemption of the 2014 Notes promptly after the calculation thereof. The Trustee shall not be responsible for calculating said Redemption Price.

     If less than all of the 2014 Notes are to be redeemed, the Trustee shall select the 2014 Notes or portions of 2014 Notes to be redeemed by such method as the Trustee shall deem fair and appropriate. The Trustee may select for redemption 2014 Notes and portions of 2014 Notes in amounts of $2,000 or any integral multiple of $1,000 in excess thereof.

     The 2014 Notes shall not have a sinking fund.

     Section 1.07. Paying Agent . The Trustee shall initially serve as Paying Agent with respect to the 2014 Notes, with the Place of Payment initially being the Corporate Trust Office.

ARTICLE II

5.05% SENIOR NOTES DUE 2019

     Section 2.01. Establishment . There is hereby established a new series of Securities to be issued under the Indenture, to be designated as the Corporation’s 5.05% Senior Notes due 2019 (the “2019 Notes”).

     There are to be authenticated and delivered $500,000,000 principal amount of the 2019 Notes, and no further 2019 Notes shall be authenticated and delivered except as provided by Section 304, 305, 306, 906 or 1106 of the Original Indenture and the last paragraph of Section 301 thereof. The 2019 Notes shall be issued in fully registered form without coupons.

     The 2019 Notes shall be in substantially the form set out in Exhibit C hereto, and the form of the Trustee’s Certificate of Authentication for the 2019 Notes shall be in substantially the form set forth in Exhibit D hereto.

     Each 2019 Note shall be dated the date of authentication thereof and shall bear interest from the date of original issuance thereof or from the most recent Interest Payment Date to which interest has been paid or duly provided for.

     Section 2.02. Definitions . The following defined terms used in this Article 2 shall, unless the context otherwise requires, have the meanings specified below for purposes of the 2019 Notes. Capitalized terms used herein for which no definition is provided herein shall have the meanings set forth in the Original Indenture.

     “Business Day” means any day other than a Saturday or a Sunday that is neither a Legal Holiday nor a day on which banking institutions in New York, New York are authorized or

required by law, regulation or executive order to close, or a day on which the Corporate Trust Office is closed for business.

     “Interest Payment Date” means each March 15 and September 15 of each year, commencing March 15, 2010.

     “Original Issue Date” means August 28, 2009.

     “Regular Record Date” means, with respect to each Interest Payment Date, the close of business on the 15th calendar day prior to such Interest Payment Date (whether or not a Business Day).

     “Stated Maturity” means September 15, 2019.

     Section 2.03. Payment of Principal and Interest . The principal of the 2019 Notes shall be due at Stated Maturity (unless earlier redeemed). The unpaid principal amount of the 2019 Notes shall bear interest at the rate of 5.05% per annum until paid or duly provided for, such interest to accrue from August 28, 2009 or from the most recent Interest Payment Date to which interest has been paid or duly provided for. Interest shall be paid semi-annually in arrears on each Interest Payment Date to the Person or Persons in whose name the 2019 Notes are registered on the Regular Record Date for such Interest Payment Date; provided that interest payable at the Stated Maturity or on a Redemption Date as provided herein shall be paid to the Person to whom principal is payable. Any such interest that is not so punctually paid or duly provided for shall forthwith cease to be payable to the Holders on such Regular Record Date and may either be paid to the Person or Persons in whose name the 2019 Notes are registered at the close of business on a Special Record Date for the payment of such defaulted interest to be fixed by the Trustee (“Special Record Date”), notice whereof shall be given to Holders of the 2019 Notes not less than ten (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, if any, on which the 2019 Notes may be listed, and upon such notice as may be required by any such exchange, all as more fully provided in the Original Indenture.

     Payments of interest on the 2019 Notes shall include interest accrued to but excluding the respective Interest Payment Dates. Interest payments for the 2019 Notes shall be computed and paid on the basis of a 360-day year of twelve 30-day months. In the event that any date on which interest is payable on the 2019 Notes is not a Business Day, then payment of the interest payable on such date shall be made on the next succeeding day that is a Business Day (and without any interest or payment in respect of any such delay) with the same force and effect as if made on the date the payment was originally payable.

     Payment of principal of, premium, if any, and interest on the 2019 Notes shall be made 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. Payments of principal of, premium, if any, and interest on 2019 Notes represented by a Global Security shall be made by wire transfer of immediately available funds to the Holder of such Global Security, provided that, in the case of payments of principal and premium, if any, such Global Security is first surrendered to the Paying Agent. If any of the 2019 Notes are no longer represented by a Global Security, (i) payments of principal,

premium, if any, and interest due at the Stated Maturity or earlier redemption of such 2019 Notes shall be made at the office of the Paying Agent upon surrender of such 2019 Notes to the Paying Agent and (ii) payments of interest shall be made, at the option of the Corporation, subject to such surrender where applicable, (A) by check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register or (B) by wire transfer at such place and to such account at a banking institution in the United States as may be designated in writing to the Trustee at least sixteen (16) days prior to the date for payment by the Person entitled thereto.

     Section 2.04. Denominations . The 2019 Notes shall be issued in denominations of $2,000 or any integral multiple of $1,000 in excess thereof.

     Section 2.05. Global Securities . The 2019 Notes shall initially be issued in the form of one or more Global Securities registered in the name of the Depositary (which initially shall be The Depository Trust Company) or its nominee. Except under the limited circumstances described below, 2019 Notes represented by such Global Security or Global Securities shall not be exchangeable for, and shall not otherwise be issuable as, 2019 Notes in definitive form. The Global Securities described in this Article 2 may not be transferred except 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 to a successor Depositary or its nominee.

     A Global Security shall be exchangeable for 2019 Notes registered in the names of persons other than the Depositary or its nominee only if (i) the Depositary notifies the Corporation that it is unwilling or unable to continue as a Depositary for such Global Security and no successor Depositary shall have been appointed by the Corporation within 90 days of receipt by the Corporation of such notification, or if at any time the Depositary ceases to be a clearing agency registered under the Exchange Act at a time when the Depositary is required to be so registered to act as such Depositary and no successor Depositary shall have been appointed by the Corporation within 90 days after it becomes aware of such cessation, (ii) an Event of Default has occurred and is continuing with respect to the 2019 Notes and beneficial owners of a majority in aggregate principal amount of the 2019 Notes represented by Global Securities advise the Depositary to cease acting as Depositary, or (iii) the Corporation in its sole discretion, and subject to the procedures of the Depositary, determines that such Global Security shall be so exchangeable. Any Global Security that is exchangeable pursuant to the preceding sentence shall be exchangeable for 2019 Notes registered in such names as the Depositary shall direct.

     Section 2.06. Redemption . The 2019 Notes shall be redeemable, in whole or from time to time in part, at the option of the Corporation on any date (a “Redemption Date”), at a Redemption Price equal to the greater of (i) 100% of the principal amount of the 2019 Notes to be redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest thereon (exclusive of interest accrued to such Redemption Date) discounted to such Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 25 basis points, plus, in either case, accrued and unpaid interest on the principal amount being redeemed to such Redemption Date.

     “Treasury Rate” means, with respect to any Redemption Date for the 2019 Notes, the rate per annum equal to the semi-annual equivalent yield to maturity or interpolated maturity (on a

day count basis) of the applicable Comparable Treasury Issue, assuming a price for such Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the applicable Comparable Treasury Price for such Redemption Date. The Treasury Rate shall be calculated on the third Business Day preceding the Redemption Date.

     “Comparable Treasury Issue” when used in this Section 2.06 means the United States Treasury security selected by the Quotation Agent as having an actual or interpolated maturity comparable to the remaining term of the 2019 Notes to be redeemed that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such 2019 Notes.

     “Quotation Agent” means a Reference Treasury Dealer appointed by the Corporation.

     “Comparable Treasury Price” means, with respect to any Redemption Date for the 2019 Notes, (1) the average of the Reference Treasury Dealer Quotations for such Redemption Date, after excluding the highest and lowest such Reference Treasury Dealer Quotations, or (2) if fewer than four such Reference Treasury Dealer Quotations are obtained, the average of all such Reference Treasury Dealer Quotations.

     “Reference Treasury Dealer” means each of BNY Mellon Capital Markets, LLC, Credit Suisse Securities (USA) LLC, J.P. Morgan Securities Inc. and RBS Securities Inc. plus one other financial institution appointed by the Corporation at the time of any redemption of the 2019 Notes or their respective affiliates which are primary U.S. Government securities dealers in the United States (a “Primary Treasury Dealer”) and their respective successors; provided, however, that if any of the foregoing or their affiliates or successors ceases to be a Primary Treasury Dealer, the Corporation will substitute therefor another Primary Treasury Dealer.

     “Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date for the 2019 Notes, the average, as determined by the Quotation Agent, of the bid and asked prices for the applicable Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Quotation Agent by such Reference Treasury Dealer at 5:00 p.m., New York City time, on the third Business Day preceding such Redemption Date.

     The Corporation shall notify the Trustee of the Redemption Price with respect to any redemption of the 2019 Notes promptly after the calculation thereof. The Trustee shall not be responsible for calculating said Redemption Price.