[Form of KU 2040 Exchange Bond]

Exhibit 4(a)-6

[Form of KU 2040 Exchange Bond]

THIS IS A GLOBAL BOND HELD BY OR ON BEHALF OF THE DEPOSITARY (AS DEFINED IN THE INDENTURE GOVERNING THIS BOND) OR ITS NOMINEE IN CUSTODY FOR THE BENEFIT OF THE BENEFICIAL OWNERS HEREOF, AND IS NOT TRANSFERABLE TO ANY PERSON UNDER ANY CIRCUMSTANCES EXCEPT THAT (I) THE TRUSTEE MAY MAKE SUCH NOTATIONS HEREON AS MAY BE REQUIRED PURSUANT TO THE INDENTURE, (II) THIS GLOBAL BOND MAY BE EXCHANGED IN WHOLE BUT NOT IN PART PURSUANT TO SECTION 2(a) OF PART II OF THE OFFICER’S CERTIFICATE ESTABLISHING THIS SERIES OF BONDS UNDER THE INDENTURE AND (III) THIS GLOBAL BOND MAY BE DELIVERED TO THE TRUSTEE FOR CANCELLATION PURSUANT TO SECTION 309 OF THE INDENTURE.

UNLESS THIS BOND 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 BOND 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 A PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

Principal Amount of $

KENTUCKY UTILITIES COMPANY

FIRST MORTGAGE BOND, 5.125% SERIES DUE 2040

KENTUCKY UTILITIES COMPANY, a corporation duly organized and existing under the laws of the Commonwealths of Kentucky and Virginia (herein referred to as the “Company”, which term includes any Successor Corporation under the Indenture referred to below), for value received, hereby promises to pay to Cede & Co. or to its registered assigns, the principal sum of                                                    ($                      ) Dollars or such principal amount as is set forth in Schedule of Exchanges of Interest in the Global Bond attached hereto on November 1, 2040 (the “Stated Maturity Date”), and to pay interest on said principal sum semi-annually in arrears on May 1 and November 1 of each year (each, an “Interest Payment Date”), at the rate of 5.125% per annum until the principal hereof is paid or made available for payment.  The first Interest Payment Date for the Securities of this series shall be May 1, 2011, and interest on the Securities of this series will accrue from and including November 16, 2010, to and excluding the first Interest Payment Date, and thereafter will accrue from and including the last Interest Payment Date to which interest on the Securities of this series has been paid or duly provided for.  No interest will accrue on the Securities of this series with respect to the day on which the Securities are paid.

CERTIFICATE OF AUTHENTICATION

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

In the event that any Interest Payment Date 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 such delay) with the same force and effect as if made on the Interest Payment Date. The interest so payable, and punctually paid or duly provided for, on any Interest Payment Date will, as provided in such 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 April 15 or October 15, whether or not a Business Day (each such date, a “Regular Record Date”), immediately preceding such Interest Payment Date, except that interest payable at Maturity will be payable to the Person to whom principal shall be paid.  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 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 referred to herein.  Interest on this Security will be computed on the basis of a 360-day year of twelve 30-day months.

Payment of the principal of and premium, if any, and interest at Maturity on this Security shall be made upon presentation of this Security at the corporate trust office of The Bank of New York Mellon in New York, New York, or at such other office or agency as may be designated for such purpose by the Company from time to time, 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, and payment of interest, if any, on this Security (other than interest payable at Maturity) shall be made by check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register, provided that if such Person is a securities depositary, such payment may be made by such other means in lieu of check as shall be agreed upon by the Company, the Trustee and such Person.

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 October 1, 2010 (herein called the “Original Indenture” and, together with any amendments or supplements thereto and the Officer’s Certificate establishing the terms of the Securities of this series, the “Indenture,” which term shall have the meaning assigned to it in the Original Indenture), between the Company and The Bank of New York Mellon, as Trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), and reference is hereby made to the Indenture, including Supplemental Indenture No. 2 thereto, for a statement of the property mortgaged, pledged and held in trust, the nature and extent of the security, the conditions upon which the lien of the Indenture may be released and 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 by the Holder hereof shall be deemed to constitute the consent and agreement by such Holder to all of the terms and provisions of the Indenture.  This Security is one of the series designated on the face hereof.

Prior to May 1, 2040, this Security is subject to redemption at the option of the Company, in whole at any time or in part from time to time, at a redemption price equal to the greater of:

(a)                                  100% of the principal amount of this Security to be so redeemed; and

(b)                                 as determined by the Quotation Agent, the sum of the present values of the remaining scheduled payments of principal and interest on the principal amount of this Security to be so redeemed (not including any portion of such payments of interest accrued to the date of redemption) discounted to the redemption date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Adjusted Treasury Rate, plus 20 basis points,

plus, in either of the above cases, accrued and unpaid interest to the date of redemption.

Promptly after the calculation thereof, the Company shall give the Trustee written notice of the redemption price for the foregoing redemption.  The Trustee shall have no responsibility for any such calculation.

On or after May 1, 2040, this Security is subject to redemption at the option of the Company, in whole at any time or in part from time to time, at a redemption price equal to 100% of the principal amount of this Security to be so redeemed, plus accrued and unpaid interest to the date of redemption.

As used herein:

“Adjusted Treasury Rate” means, with respect to any redemption date, the rate per annum equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for that redemption date.

“Comparable Treasury Issue” means the United States Treasury security selected by the Quotation Agent as having an actual or interpolated maturity comparable to the remaining term to the Stated Maturity Date of this Security 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 this Security.

“Comparable Treasury Price” means, with respect to any redemption date:

a)                                      the average of five Reference Treasury Dealer Quotations for that redemption date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or

b)                                     if the Quotation Agent obtains fewer than five Reference Treasury Dealer Quotations, the average of all Reference Treasury Dealer Quotations so received.

“Quotation Agent” means one of the Reference Treasury Dealers appointed by the Company.

“Reference Treasury Dealer” means:

a)                                      each of Credit Suisse Securities (USA) LLC and Merrill Lynch, Pierce, Fenner & Smith Incorporated, and their respective successors, unless any of them ceases to be a primary U.S. Government securities dealer in the United States (a “Primary Treasury Dealer”), in which case the Company shall substitute another Primary Treasury Dealer; and

b)                                     any other Primary Treasury Dealers selected by the Company (after consultation with the Quotation Agent).

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

Notice of redemption shall be given by mail to Holders of Securities, not less than 30 days nor more than 60 days prior to the date fixed for redemption, all as provided in the Indenture.  As provided in the Indenture, notice of redemption at the election of the Company as aforesaid may state that such redemption shall be conditional upon the receipt by the applicable Paying Agent or Agents of money

sufficient to pay the principal of and premium, if any, and interest, on this Security on or prior to the date fixed for such redemption; a notice of redemption so conditioned shall be of no force or effect if such money is not so received and, in such event, the Company shall not be required to redeem this Security.

In the event of redemption of this Security in part only, a new Security or Securities of this series of like tenor representing the unredeemed portion hereof shall be issued in the name of the Holder hereof upon the cancellation hereof.

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

The Indenture contains provisions for defeasance at any time of the entire indebtedness of this Security upon compliance with certain conditions set forth 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.  The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of all series affected at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company with 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 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.

As provided in and subject to the provisions of the Indenture, the Holder of this Security 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 (a) such Holder shall have previously given the Trustee written notice of a continuing Event of Default; (b) the Holders of 25% in aggregate principal amount of the Outstanding Securities 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; (c) the Trustee shall not have received from the Holders of a majority in aggregate principal amount of the Outstanding Securities a direction inconsistent with such request; and (d) 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 Security for the enforcement of any payment of principal hereof or any premium or interest hereon on or after the respective due dates expressed herein.

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 any premium and interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

The Securities of this series are issuable only in registered form without coupons, and in denominations of $2,000 and integral multiples of $1,000 in excess thereof.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register, upon surrender of this Security for registration of transfer at the office or agency of the Company for such purpose, duly endorsed by, or accompanied by a written

instrument or transfer in form satisfactory to the Company and the Trustee duly executed by, the Holder hereof or his attorney duly authorized in writing, and thereupon one or more new Securities of this series and Tranche, of authorized denominations and of like tenor and aggregate principal amount, shall be issued to the designated transferee or transferees.

As provided in the Indenture and subject to certain limitations therein set forth, Securities of this series and Tranche are exchangeable for a like aggregate principal amount of Securities of the same series and Tranche of any authorized denominations, as requested by the Holder surrendering the same, and of like tenor upon surrender of the Security or Securities to be exchanged at the office or agency of the Company for such purpose.

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 cover any tax or other governmental charge payable in connection therewith.

The Company shall not be required to execute and the Security Registrar shall not be required to register the transfer of or exchange of (a) Securities of this series during a period of 15 days immediately preceding the date notice is given identifying the serial numbers of the Securities of this series called for redemption or (b) any Security so selected for redemption in whole or in part, except the unredeemed portion of any Security being redeemed in part.

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 absolute owner hereof for all purposes (subject to Sections 305 and 307 of the Indenture), 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.

The Indenture and this Security shall be governed by and construed in accordance with the laws of the State of New York (including, without limitation, Section 5-1401 of the New York General Obligations Law or any successor to such statute), except to the extent that the Trust Indenture Act shall be applicable and except to the extent that the law of the any other jurisdiction shall mandatorily govern.

As used herein, “Business Day,” means any day, other than a Saturday or Sunday, that is not a day on which banking institutions or trust companies in The City of New York, New York, or other city in which a paying agent for this Security is located, are generally authorized or required by law, regulation or executive order to remain closed.  All other terms used in this Security that are defined in the Indenture shall have the meanings assigned to them in the Indenture.

As provided in the Indenture, no recourse shall be had for the payment of the principal of or premium, if any, or interest on any Securities, or any part thereof, or for any claim based thereon or otherwise in respect thereof, or of the indebtedness represented thereby, or upon any obligation, covenant or agreement under the Indenture, against, and no personal liability whatsoever shall attach to, or be incurred by, any incorporator, stockholder, member, officer or director, as such, past, present or future of the Company or of any predecessor or successor corporation (either directly or through the Company or a predecessor or successor corporation), whether by virtue of any constitutional provision, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise; it being expressly agreed and understood that the Indenture and all the Securities are solely corporate obligations and that any such personal liability is hereby expressly waived and released as a condition of, and as part of the consideration for, the execution of the Indenture and the issuance of the Securities.

Unless the certificate of authentication hereon has been executed by the Trustee referred to herein 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.

SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL BOND

The following exchanges of a part of this Global Bond for an interest in another Global Bond, or exchanges of a part of another Global Bond for an interest in this Global Bond, have been made:

ASSIGNMENT FORM

FOR VALUE RECEIVED the undersigned hereby sells, assigns and transfers unto

the within Security of KENTUCKY UTILITIES COMPANY and does hereby irrevocably constitute and appoint                                          , Attorney,  to transfer said Security on the books of the within-mentioned Company, with full power of substitution in the premises.

Dated:

Notice:  The signature to this assignment must correspond with the name as written upon the face of the Security in every particular without alteration or enlargement or any change whatsoever.

SIGNATURE GUARANTEE

(Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Security Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Security Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.)