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                                                                    EXHIBIT 4.11


                                    GUARANTEE

                  This GUARANTEE (this "Guarantee") is entered into as of March
30, 2000 by LOUISIANA GENERATING LLC, a Delaware limited liability company, (the
"Subsidiary Guarantor"), in favor of THE CHASE MANHATTAN BANK, a New York
banking corporation (the "Bond Trustee"). All capitalized terms used herein but
not specifically defined shall have the respective meanings given to such terms
in Appendix A to the Indenture, which Appendix A is hereby incorporated herein
by reference as if set forth in full herein.

                              W I T N E S S E T H:

                  WHEREAS, NRG South Central Generating LLC, a Delaware limited
liability company (the "Issuer"), has on the date hereof issued and sold the
Bonds pursuant to the Indenture and has loaned a portion of the proceeds of such
sale to the Subsidiary Guarantor on the terms and conditions set forth in the
Guarantor Loan Agreement; and

                  WHEREAS, the Subsidiary Guarantor is a wholly owned subsidiary
of the Issuer and anticipates benefitting directly and indirectly from the
issuance and sale of the Bonds by the Issuer and, therefore, is willing to
guarantee certain of the obligations of the Issuer thereunder in accordance with
the terms hereof.

                  NOW, THEREFORE, in consideration of the above premises and for
other good and valuable consideration, the receipt and adequacy of which are
hereby acknowledged, the parties hereto hereby agree as follows:

                  1. The Subsidiary Guarantor hereby guarantees to each Holder
and the Bond Trustee and their respective successors and assigns the prompt
payment in full when due (whether at stated maturity, by acceleration or
otherwise) of the principal of and interest on the Bonds and all other amounts
(including the reasonable fees and expenses of counsel) from time to time owing
to the Holders or the Bond Trustee by the Issuer under the Indenture and any
Supplemental Indenture and by any Obligor or any Additional Guarantor under any
of the other Finance Documents strictly in accordance with the terms thereof
(such obligations being herein collectively called the "Guaranteed
Obligations"). The Subsidiary Guarantor hereby agrees that if the Issuer shall
fail to pay in full when due (whether at stated maturity, by acceleration or
otherwise) any of the Guaranteed Obligations, the Subsidiary Guarantor will
promptly pay the same, without any demand or notice
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whatsoever, and that in the case of any extension of time of payment or renewal
of any of the Guaranteed Obligations, the same will be promptly paid in full
when due (whether at extended maturity, by acceleration or otherwise) in
accordance with the terms of such extension or renewal.

                  2. The obligations of the Subsidiary Guarantor under Section 1
are absolute and unconditional irrespective of the value, genuineness, validity,
regularity or enforceability of the obligations of the Issuer under the
Indenture or any other agreement or instrument referred to therein, or any
substitution, release or exchange of any other guarantee of or security for any
of the Guaranteed Obligations, and, to the fullest extent permitted by
applicable law, irrespective of any other circumstance whatsoever that might
otherwise constitute a legal or equitable discharge or defense of a surety or
guarantor, it being the intent of this Section that the obligations of the
Subsidiary Guarantor hereunder shall be absolute and unconditional under any and
all circumstances. Without limiting the generality of the foregoing, it is
agreed that the occurrence of any one or more of the following shall not alter
or impair the liability of the Subsidiary Guarantor, which shall remain absolute
and unconditional as described above:

                  (i) at any time or from time to time, without notice to the
         Subsidiary Guarantor, the time for any performance of or compliance
         with any of the Guaranteed Obligations shall be extended, or such
         performance or compliance shall be waived;

                  (ii) any of the acts mentioned in any of the provisions of the
         Indenture or any other agreement or instrument referred to therein
         shall be done or omitted;

                  (iii) the maturity of any of the Guaranteed Obligations shall
         be accelerated, or any of the Guaranteed Obligations shall be modified,
         supplemented or amended in any respect, or any right under the
         Indenture or any other agreement or instrument referred to therein
         shall be waived or any other guarantee of any of the Guaranteed
         Obligations or any security therefor shall be released or exchanged in
         whole or in part or otherwise dealt with; or

                  (iv) any Lien or security interest granted to, or in favor of,
         the Bond Trustee, the Collateral Agent or any Holder or Holders as
         security for any of the Guaranteed Obligations shall fail to be
         perfected.


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The Subsidiary Guarantor hereby expressly waives diligence, presentment, demand
of payment, demand for performance, protest and all notices whatsoever,
including without limitation notice of the existence, creation or incurrence of
new or additional Guaranteed Obligations and notice of acceptance of this
Guarantee, and any requirement that the Bond Trustee or any Holder exhaust any
right, power or remedy or proceed against the Issuer under the Indenture or any
other agreement or instrument referred to therein, or against any other Person
under any other guarantee of, or security for, any of the Guaranteed
Obligations.

                  3. The obligations of the Subsidiary Guarantor under this
Agreement shall be automatically reinstated if and to the extent that for any
reason any payment by or on behalf of the Issuer in respect of the Guaranteed
Obligations is rescinded or must be otherwise restored by any holder of any of
the Guaranteed Obligations, whether as a result of any proceedings in bankruptcy
or reorganization or otherwise, and the Subsidiary Guarantor agrees that it will
indemnify the Bond Trustee and each Holder on demand for all reasonable costs
and expenses (including reasonable fees of counsel) incurred by the Bond Trustee
or such Holder in connection with such rescission or restoration, including any
such costs and expenses incurred in defending against any claim alleging that
such payment constituted a preference, fraudulent transfer or similar payment
under any bankruptcy, insolvency or similar law.

                  4. The Subsidiary Guarantor hereby agrees that, until the
payment and satisfaction in full of all Guaranteed Obligations and the
satisfaction and discharge of the Bonds under the Indenture and any Supplemental
Indenture, it shall not exercise any right or remedy arising by reason of any
performance by it of its guarantee in Section 1, whether by subrogation or
otherwise, against the Issuer or any other guarantor of any of the Guaranteed
Obligations or any security for any of the Guaranteed Obligations.

                  5. The Subsidiary Guarantor hereby agrees that, as between the
Subsidiary Guarantor and the Holders, the obligations of the Issuer under the
Indenture may be declared to be forthwith due and payable pursuant to the
provisions of the Indenture (and shall be deemed to have become automatically
due and payable in the circumstances provided in the Indenture) for purposes of
Section 1 notwithstanding any stay, injunction or other prohibition preventing
such declaration (or such obligations from becoming automatically due and
payable) as against the Issuer, and that, in the event of such declaration (or
such obligations being deemed to have become automatically due and payable),
such obligations (whether or not due and


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payable by the Issuer) shall forthwith become due and payable by the Subsidiary
Guarantor for purposes of Section 1.

                  6. The Subsidiary Guarantor hereby acknowledges that the
guarantee in this Guarantee constitutes an instrument for the payment of money,
and consents and agrees that any Holder or the Bond Trustee, at its sole option,
in the event of a dispute by such Subsidiary Guarantor in the payment of any
moneys due hereunder, shall have the right to bring motion-action under New York
CPLR Section 3213.

                  7. The guarantee in this Guarantee is a continuing guarantee
of payment and shall apply to all Guaranteed Obligations whenever arising.

                  8. The obligation of the Subsidiary Guarantor to pay the
Guaranteed Obligations as set forth in this Guarantee shall terminate upon the
Debt Termination Date.

                  9. In any action or proceeding involving any state corporate
law, or any state or federal bankruptcy, insolvency, reorganization or other law
affecting the rights of creditors generally, if the obligations of the
Subsidiary Guarantor under Section 1 would otherwise be held or determined to be
void, invalid or unenforceable, or subordinated to the claims of any other
creditors, on account of the amount of its liability under Section 1, then,
notwithstanding any other provision hereof to the contrary, the amount of such
liability shall, without any further action by the Subsidiary Guarantor, any
Holder, the Bond Trustee or any other Person, be automatically limited and
reduced to the highest amount that is valid and enforceable and not subordinated
to the claims of other creditors as determined in such action or proceeding.

                  10. The obligations hereunder are independent of the
obligations of the Issuer or any Additional Guarantor, and a separate action or
actions may be brought and prosecuted against the Subsidiary Guarantor whether
action is brought against either the Issuer or any other Additional Guarantor,
or whether either the Issuer or any Additional Guarantor be joined in any such
action or actions, and to the extent permitted by Applicable Law, the Subsidiary
Guarantor waives the benefit of any statute of limitations affecting its
liability hereunder. Each and every failure in the payment of any of the
Guaranteed Obligations shall give rise to a separate cause of action under this
Guarantee, and separate suits may be brought against the Subsidiary Guarantor
hereunder as each cause of action arises.


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                  11. The Subsidiary Guarantor represents and warrants that:

                  (a) Power and Authority. The Subsidiary Guarantor has the
limited liability company power and authority to (i) execute and deliver this
Guarantee and perform its obligations hereunder, (ii) to conduct its business as
currently conducted and (iii) to own its property.

                  (b) Valid Existence. The Subsidiary Guarantor is duly
organized and is validly existing under and pursuant to the laws of the
jurisdiction of its organization and is qualified to do business and is in good
standing in all jurisdictions necessary for it to conduct its business and own
its property except where the failure to so qualify or be in good standing would
not have a Material Adverse Effect.

                  (c) Due Authorization. The execution, delivery and performance
by the Subsidiary Guarantor of this Guarantee have been duly authorized by all
necessary corporate action, and do not and shall not require any further
consents or approvals which have not been obtained, or violate any provision of
any law or breach any agreement presently in effect with respect to or binding
on the Subsidiary Guarantor or its properties except where such violations or
breach would not have a Material Adverse Effect.

                  (d) Binding Obligation. This Guarantee is a legal, valid and
binding obligation of the Subsidiary Guarantor, enforceable against it in
accordance with its terms, except as such enforceability may be limited in each
case by bankruptcy, insolvency, fraudulent conveyance, reorganization,
moratorium or similar laws affecting the enforceability of creditors' rights
generally (and to the possible judicial application of foreign laws or
governmental action affecting the rights of creditors generally) and except as
such enforceability is subject to the application of general principles of
equity (regardless of whether the issue of enforceability is considered in a
proceeding in equity or at law), including without limitation (i) the possible
unavailability of specific performance, injunctive relief or any other equitable
remedy and (ii) concepts of materiality, reasonableness, good faith and fair
dealing.

                  12. To the extent that the covenant set forth in Section 4 is
or is deemed to be ineffective or inapplicable, any obligations of the Issuer to
the Subsidiary Guarantor, now or hereafter existing, are hereby subordinated to
the Guaranteed


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Obligations. After the occurrence of an Event of Default, such obligations of
the Issuer to the Subsidiary Guarantor shall be enforced and performance
received by the Subsidiary Guarantor as trustee for the Bond Trustee and the
proceeds thereof shall be paid over to the Bond Trustee on account of the
Guaranteed Obligations, but without reducing or affecting in any manner the
maximum liability of the Subsidiary Guarantor under the other provisions of this
Guarantee.

                  13. The Bond Trustee may, without notice to the Subsidiary
Guarantor and without affecting the Subsidiary Guarantor's obligations
hereunder, assign this Guarantee, in whole or in part in accordance with the
provisions of the Indenture. The Subsidiary Guarantor agrees that the Bond
Trustee may, subject to the provisions of the Indenture, disclose to any
prospective purchaser and any purchaser of all or part of the Guaranteed
Obligations any and all information in the Bond Trustee's possession concerning
the Subsidiary Guarantor, this Guarantee and any security for this Guarantee.

                  14. The Bond Trustee agrees that no members (other than the
Issuer), directors, officers, shareholders or employees or agents of the
Subsidiary Guarantor shall in any way be liable for the payment of the Bonds,
the Guarantor Note or any sums now or hereafter owing under the terms of, or for
the performance of any obligation contained in, this Guarantee.

                  15. No modification or waiver of any of the provisions of this
Guarantee shall be binding on the Bond Trustee, except as expressly set forth in
a writing duly signed and delivered by the Bond Trustee acting pursuant to the
terms or Article 8 of the Indenture.

                  16. This Guarantee shall be binding upon and inure to the
benefit of the Subsidiary Guarantor and the Bond Trustee for the benefit of the
Secured Parties and their respective successors and assigns; provided that the
Subsidiary Guarantor shall not assign its rights or the Guaranteed Obligations
created under this Guarantee without the prior written consent of the Bond
Trustee.

                  17. In case any provision of this Guarantee or the Bonds shall
be invalid, illegal or unenforceable in any jurisdiction, the validity, legality
and enforceability of the remaining provisions or the Guaranteed Obligations, or
of such provision or the Guaranteed Obligations in any jurisdiction, shall not
in any way be affected or impaired thereby.


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                  18. THIS GUARANTEE IS A CONTRACT MADE UNDER THE LAWS OF THE
STATE OF NEW YORK OF THE UNITED STATES AND SHALL FOR ALL PURPOSES BE GOVERNED BY
AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF SUCH STATE WITHOUT REGARD TO THE
CONFLICT OF LAW RULES THEREOF (OTHER THAN SECTION 5-1401 OF THE NEW YORK GENERAL
OBLIGATIONS LAW).

                  19. Any legal action or proceeding against the Subsidiary
Guarantor with respect to this Guarantee may be brought in the courts of the
State of New York in the County of New York or of the United States for the
Southern District of New York and, by execution and delivery of this Guarantee,
the Subsidiary Guarantor hereby irrevocably submits and accepts for itself and
in respect of its property, generally and unconditionally, the jurisdiction of
the aforesaid courts. The Subsidiary Guarantor agrees that a judgment, after
exhaustion of all available appeals, in any such action or proceeding shall be
conclusive and binding upon the Subsidiary Guarantor. The Subsidiary Guarantor
hereby irrevocably designates, appoints and empowers CT Corporation System with
offices on the date hereof at 111 Eighth Avenue, New York, N.Y. 10011, as its
designee, appointee and agent to receive, accept and acknowledge for and on its
behalf, and in respect of its property, service of any and all legal process,
summons, notices and documents which may be served in any such action or
proceeding. If for any reason such designee, appointee and agent shall cease to
be available to act as such, the Subsidiary Guarantor agrees to designate a new
designee, appointee and agent in New York City on the terms and for the purposes
of this provision satisfactory to the Bond Trustee. The Subsidiary Guarantor
further irrevocably consents to the service of process out of any of the
aforementioned courts in any such action or proceeding by the mailing of copies
thereof by registered or certified mail, postage prepaid, to the Subsidiary
Guarantor at its address referred to in Section 23, such service to become
effective thirty (30) days after such mailing. Nothing herein shall affect the
right of the Bond Trustee to serve process in any other manner permitted by law
or to commence legal proceedings or otherwise proceed against the Subsidiary
Guarantor in any other jurisdiction.

                  20. The Subsidiary Guarantor hereby irrevocably waives any
objection which it may now or hereafter have to the laying of venue of any of
the aforesaid actions or proceedings arising out of or in connection with this
Guarantee brought in the courts referred to in clause (b) above and hereby
further irrevocably waives and agrees not to plead or claim in any such court
that any such action or proceeding brought in any such court has been brought in
an inconvenient forum.


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                  21. WITH REGARD TO THIS GUARANTEE, EACH OF THE SUBSIDIARY
GUARANTOR AND THE BOND TRUSTEE HEREBY WAIVES THE RIGHTS TO A TRIAL BY JURY IN
ANY ACTION OR PROCEEDING AND FOR ANY COUNTERCLAIM THEREIN.

                  22. This Guarantee embodies the entire agreement and
understanding between the parties hereto and supersedes all prior agreements and
understandings relating to the subject matter hereof.

                  23. All notices, demands, requests and other communications
required or permitted hereunder shall be in writing, and shall be given and
deemed to have been given in accordance with Section 12.5 of the Indenture at
the addresses set forth for the Subsidiary Guarantor and the Bond Trustee on
Schedule III to the Indenture.

                  24. This Guarantee may be executed in any number of
counterparts, all of which together shall constitute one agreement.


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                  IN WITNESS WHEREOF, the parties hereto have caused this
Guarantee to be duly executed as of the day and year first written above.


                                LOUISIANA GENERATING LLC




                                By: /s/ Craig A. Mataczynski
                                    ----------------------------------
                                    Name:  Craig A. Mataczynski
                                    Title: Vice President



                                THE CHASE MANHATTAN BANK
                                solely in its capacity as Bond Trustee




                                By: /s/ Annette M. Marsula
                                    ----------------------------------
                                    Name: Annette M. Marsula
                                    Title: Vice President


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