Exhibit 4(d)


                                 GUARANTEE AGREEMENT

                                       Between

                           Minnesota Power & Light Company
                                    (as Guarantor)

                                         and

                                 The Bank of New York
                                     (as Trustee)

                                     dated as of

                                                  , 1996




          
                                  TABLE OF CONTENTS
                                  -----------------

                                                                       Page
                                                                       ----

          ARTICLE I    DEFINITIONS  . . . . . . . . . . . . . . . . . .   1
               SECTION 1.01 Definitions   . . . . . . . . . . . . . . .   1

          ARTICLE II   TRUST INDENTURE ACT  . . . . . . . . . . . . . .   4
               SECTION 2.01 Trust Indenture Act; Application  . . . . .   4
               SECTION 2.02 Lists of Holders of Preferred Securities  .   4
               SECTION 2.03 Reports by the Guarantee Trustee  . . . . .   4
               SECTION 2.04 Periodic Reports to Guarantee Trustee   . .   4
               SECTION 2.05 Evidence of Compliance with Conditions
                       Precedent  . . . . . . . . . . . . . . . . . . .   5
               SECTION 2.06 Events of Default; Waiver   . . . . . . . .   5
               SECTION 2.07 Event of Default; Notice  . . . . . . . . .   5
               SECTION 2.08 Conflicting Interests   . . . . . . . . . .   5



          ARTICLE III  POWERS, DUTIES AND RIGHTS OF GUARANTEE TRUSTEE .   5
               SECTION 3.01 Powers and Duties of the Guarantee
                       Trustee  . . . . . . . . . . . . . . . . . . . .   5
               SECTION 3.02 Certain Rights of Guarantee Trustee   . . .   7

          ARTICLE IV   GUARANTEE TRUSTEE  . . . . . . . . . . . . . . .   9
               SECTION 4.01 Guarantee Trustee; Eligibility  . . . . . .   9
               SECTION 4.02 Compensation and Reimbursement  . . . . . .   9
               SECTION 4.03 Appointment, Removal and Resignation of
                              Guarantee Trustee   . . . . . . . . . . .  10

          ARTICLE V    GUARANTEE  . . . . . . . . . . . . . . . . . . .  11
               SECTION 5.01 Guarantee   . . . . . . . . . . . . . . . .  11
               SECTION 5.02 Waiver of Notice and Demand   . . . . . . .  11
               SECTION 5.03 Obligations Not Affected  . . . . . . . . .  12
               SECTION 5.04 Rights of Holders   . . . . . . . . . . . .  12
               SECTION 5.05 Guarantee of Payment  . . . . . . . . . . .  13
               SECTION 5.06 Subrogation   . . . . . . . . . . . . . . .  13
               SECTION 5.07 Independent Obligations   . . . . . . . . .  13

          ARTICLE VI   SUBORDINATION  . . . . . . . . . . . . . . . . .  13
               SECTION 6.01 Subordination   . . . . . . . . . . . . . .  13

          ARTICLE VII  TERMINATION  . . . . . . . . . . . . . . . . . .  14
               SECTION 7.01 Termination   . . . . . . . . . . . . . . .  14

          ARTICLE VIII      MISCELLANEOUS   . . . . . . . . . . . . . .  14
               SECTION 8.01 Successors and Assigns  . . . . . . . . . .  14
               SECTION 8.02 Amendments  . . . . . . . . . . . . . . . .  14
               SECTION 8.03 Notices   . . . . . . . . . . . . . . . . .  14
               SECTION 8.04 Benefit   . . . . . . . . . . . . . . . . .  15
               SECTION 8.05 Interpretation  . . . . . . . . . . . . . .  16
               SECTION 8.06 Governing Law   . . . . . . . . . . . . . .  16

          
                                CROSS-REFERENCE TABLE
                                ---------------------


          Section of                                             Section of
          Trust Indenture Act                                     Guarantee
          of 1939, as amended                                    Agreement 
          -------------------                                    ----------

          S310(a) . . . . . . . . . . . . . . . . . . . . .   4.01(a)      
          310(b)  . . . . . . . . . . . . . . . . . . . . .   4.01(c), 2.08
          310(c)  . . . . . . . . . . . . . . . . . . . . .   Inapplicable 
          311(a)  . . . . . . . . . . . . . . . . . . . . .   2.02(b)      
          311(b)  . . . . . . . . . . . . . . . . . . . . .   2.02(b)      
          311(c)  . . . . . . . . . . . . . . . . . . . . .   Inapplicable 
          312(a)  . . . . . . . . . . . . . . . . . . . . .   2.02(a)      
          312(b)  . . . . . . . . . . . . . . . . . . . . .   2.02(b)      
          313 . . . . . . . . . . . . . . . . . . . . . . .   2.03         
          314(a)  . . . . . . . . . . . . . . . . . . . . .   2.04         
          314(b)  . . . . . . . . . . . . . . . . . . . . .   Inapplicable 
          314(c)  . . . . . . . . . . . . . . . . . . . . .   2.05         
          314(d)  . . . . . . . . . . . . . . . . . . . . .   Inapplicable 
          314(e)  . . . . . . . . . . . . . . . . . . . . .   1.01, 2.05,  
                                                              3.02         
          314(f)  . . . . . . . . . . . . . . . . . . . . .   2.01, 3.02
          315(a)  . . . . . . . . . . . . . . . . . . . . .   3.01(d)      
          315(b)  . . . . . . . . . . . . . . . . . . . . .   2.07         
          315(c)  . . . . . . . . . . . . . . . . . . . . .   3.01         
          315(d)  . . . . . . . . . . . . . . . . . . . . .   3.01(d)      
          316(a)  . . . . . . . . . . . . . . . . . . . . .   5.04(a), 2.06
          316(b)  . . . . . . . . . . . . . . . . . . . . .   5.03         
          316(c)  . . . . . . . . . . . . . . . . . . . . .   2.02         
          317(a)  . . . . . . . . . . . . . . . . . . . . .   Inapplicable 
          317(b)  . . . . . . . . . . . . . . . . . . . . .   Inapplicable 
          318(a)  . . . . . . . . . . . . . . . . . . . . .   2.01(b),     
          318(b)  . . . . . . . . . . . . . . . . . . . . .   2.01         
          318(c)  . . . . . . . . . . . . . . . . . . . . .   2.01(a)      

          _____________
          *    This Cross-Reference Table does not constitute part of the
               Guarantee Agreement and shall not affect the interpretation
               of any of its terms or provisions.



          
                                 GUARANTEE AGREEMENT

                    This GUARANTEE AGREEMENT ("Guarantee Agreement"), dated
          as of           , 1996, is executed and delivered by Minnesota
          Power & Light Company, a Minnesota corporation (the "Guarantor"),
          and The Bank of New York, as trustee (the "Guarantee Trustee"),
          for the benefit of the Holders (as defined herein) from time to
          time of the Preferred Securities (as defined herein) of MP&L
          Capital I, a Delaware statutory business trust (the "Issuer").

                    WHEREAS, pursuant to an Amended and Restated Trust
          Agreement (the "Trust Agreement"), dated as of             , 1996
          between the Trustees of the Issuer named therein, Minnesota Power
          & Light Company, as Depositor, and the several Holders (as
          defined therein) the Issuer is issuing as of the date hereof 
          $           aggregate liquidation amount of its     % Cumulative
          Quarterly Income Preferred Securities (the "Preferred
          Securities") representing ownership interests in the Issuer and
          having the terms set forth in the Trust Agreement;

                    WHEREAS, the Preferred Securities are to be issued for
          sale by the Issuer and the proceeds are to be invested in 
          $         principal amount of Debentures (as defined in the Trust
          Agreement); and 

                    WHEREAS, in order to enhance the value of the Preferred
          Securities, the Guarantor desires to irrevocably and
          unconditionally agree, to the extent set forth herein, to pay to
          the Holders the Guarantee Payments (as defined herein) and to
          make certain other payments on the terms and conditions set forth
          herein;
          
                    NOW, THEREFORE, in consideration of the purchase of
          Debentures, which purchase the Guarantor hereby agrees shall
          benefit the Guarantor, the Guarantor executes and delivers this
          Guarantee Agreement for the benefit of the Holders from time to
          time.


                                      ARTICLE I

                                     DEFINITIONS

                    SECTION 1.01        DEFINITIONS.  AS USED IN THIS
          GUARANTEE AGREEMENT, THE TERMS SET FORTH BELOW SHALL, UNLESS THE
          CONTEXT OTHERWISE REQUIRES, HAVE THE FOLLOWING MEANINGS. 
          CAPITALIZED OR OTHERWISE DEFINED TERMS USED BUT NOT OTHERWISE
          DEFINED HEREIN SHALL HAVE THE MEANINGS ASSIGNED TO SUCH TERMS IN
          THE TRUST AGREEMENT AS IN EFFECT ON THE DATE HEREOF.

                    "Affiliate" of any specified Person means any other
          Person directly or indirectly controlling or controlled by or
          under direct or indirect common control with such specified
          Person.  For the purposes of this definition, "control" when used
          with respect to any specified Person means the power to direct
          the management and policies of such Person, directly or
          indirectly, whether through the ownership of voting securities,
          by contract or otherwise; and the terms "controlling" and
          "controlled" have meanings correlative to the
          foregoing.

                    "Common Securities" means the securities representing
          common ownership interests in the assets of the Issuer.

                    "Event of Default" means a default by the Guarantor on
          any of its payment obligations under this Guarantee Agreement.

                    "Guarantee Payments" shall mean the following payments
          or distributions, without duplication, with respect to the
          Preferred Securities, to the extent not paid or made by or on
          behalf of the Issuer: (i) any accrued and unpaid Distributions
          that are required to be paid on such Preferred Securities but
          only if and to the extent that the Property Trustee has available
          in the Payment Account funds sufficient to make such payment,
          (ii) the redemption price (the "Redemption Price"), and all
          accrued and unpaid Distributions to the date of redemption, with
          respect to the Preferred Securities called for redemption by the
          Issuer but only if and to the extent that the Property Trustee
          has available in the Payment Account funds sufficient to make
          such payment, (iii) upon a voluntary or involuntary dissolution,
          winding-up or termination of the Issuer (other than in connection
          with a redemption of all of the Preferred Securities), the lesser
          of (a) the aggregate of the Liquidation Amount and all accrued
          and unpaid Distributions on the Preferred Securities to the date
          of payment but only if and to the extent that the Property
          Trustee has available in the Payment Account funds sufficient to
          make such payment, and (b) the amount of assets of the Issuer
          remaining available for distribution to Holders in liquidation of
          the Issuer (in either case, the "Liquidation Distribution").

                    "Guarantee Trustee" means The Bank of New York until a
          Successor Guarantee Trustee has been appointed and has accepted
          such appointment pursuant to the terms of this Guarantee
          Agreement and thereafter means each such Successor Guarantee
          Trustee.

                    "Holder" shall mean any holder, as registered on the
          books and records of the Issuer, of any Preferred Securities then
          outstanding; provided, however, that in determining whether the
          holders of the requisite percentage of Preferred Securities have
          given any request, notice, consent or waiver hereunder, "Holder"
          shall not include the Guarantor or any Affiliate of the
          Guarantor.

                    "Indenture" means the Indenture dated as of             
               , 1996, among the Guarantor (the "Debenture Issuer") and The
          Bank of New York, as trustee pursuant to which the Debentures are
          issued.

                    "Majority in liquidation amount of the Preferred
          Securities" means a vote by Holders, voting separately as a
          class, of more than 50% of the aggregate liquidation amount of
          all Preferred Securities.

                    "Officers' Certificate" means a certificate signed by
          the Chairman of the Board, a Vice Chairman of the Board, the
          President or a Vice President, and by the Treasurer, an Assistant
          Treasurer, the Secretary or an Assistant Secretary, of the
          Guarantor, and delivered to the Guarantee Trustee.  Any Officers'
          Certificate delivered with respect to compliance with a condition
          or covenant provided for in this Guarantee Agreement shall
          include:

                    (a)  a statement that each officer signing the
               Officers' Certificate has read the covenant or condition and
               the definitions relating thereto;

                    (b)  a brief statement of the nature and scope of the
               examination or investigation undertaken by each officer in
               rendering the Officers' Certificate;

                    (c)  a statement that each such officer has made such
               examination or investigation as, in such officer's opinion,
               is necessary to enable such officer to express an informed
               opinion as to whether or not such covenant or condition has
               been complied with; and

                    (d)  a statement as to whether, in the opinion of each
               such officer, such condition or covenant has been complied
               with.
               
                    "Person" means any individual, corporation,
          partnership, joint venture, trust, unincorporated organization or
          government or any agency or political subdivision thereof.

                    "Responsible Officer" means, with respect to the
          Guarantee Trustee, any vice-president, any assistant vice-
          president, the secretary, any assistant secretary, the treasurer,
          any assistant treasurer, any trust officer or assistant trust
          officer or any other officer of the Corporate Trust Department of
          the Guarantee Trustee customarily performing functions similar to
          those performed by any of the above designated officers and also
          means, with respect to a particular corporate trust matter, any
          other officer to whom such matter is referred because of that
          officer's knowledge of and familiarity with the particular
          subject.

                    "Successor Guarantee Trustee" means a successor
          Guarantee Trustee possessing the qualifications to act as
          Guarantee Trustee under Section 4.01.

                    "Trust Indenture Act" means the Trust Indenture Act of
          1939, as amended.


                                      ARTICLE II

                                 TRUST INDENTURE ACT

                    SECTION 2.01        TRUST INDENTURE ACT; APPLICATION.

                    (a)  This Guarantee Agreement is subject to the
          provisions of the Trust Indenture Act that are required or deemed
          to be part of this Guarantee Agreement and shall, to the extent
          applicable, be governed by such provisions; and

                    (b)  if and to the extent that any provision of this
          Guarantee Agreement limits, qualifies or conflicts with the
          duties imposed by Sections 310 to 317, inclusive, of the Trust
          Indenture Act, such imposed duties shall control.

                    SECTION 2.02        LISTS OF HOLDERS OF PREFERRED
          SECURITIES.

                    (a)  The Guarantor shall furnish or cause to be
          furnished to the Guarantee Trustee (a) semiannually, not later
          than December 31 and June 30 in each year, a list, in such form
          as the Guarantee Trustee may reasonably require, of the names and
          addresses of the Holders ("List of Holders") as of a date not
          more than 15 days prior to the delivery thereof, and (b) at such
          other times as the Guarantee Trustee may request in writing,
          within 30 days after the receipt by the Guarantor of any such
          request, a List of Holders as of a date not more than 15 days
          prior to the time such list is furnished; provided that, the
          Guarantor shall not be obligated to provide such List of Holders
          at any time the List of Holders does not differ from the most
          recent List of Holders given to the Guarantee Trustee by the
          Guarantor.  The Guarantee Trustee may destroy any List of Holders
          previously given to it on receipt of a new List of Holders.

                    (b)  The Guarantee Trustee shall comply with its
          obligations under Section 311(a) of the Trust Indenture Act,
          subject to the provisions of Section 311(b) and Section 312(b) of
          the Trust Indenture Act.

                    SECTION 2.03        REPORTS BY THE GUARANTEE TRUSTEE. 
          WITHIN 60 DAYS AFTER DECEMBER 31 OF EACH YEAR, COMMENCING
          DECEMBER 31, 1996, THE GUARANTEE TRUSTEE SHALL PROVIDE TO THE
          HOLDERS SUCH REPORTS, IF ANY, AS ARE REQUIRED BY SECTION 313(A)
          OF THE TRUST INDENTURE ACT IN THE FORM AND IN THE MANNER PROVIDED
          BY SECTION 313(A) OF THE TRUST INDENTURE ACT.  THE GUARANTEE
          TRUSTEE SHALL ALSO COMPLY WITH THE REQUIREMENTS OF SECTIONS
          313(B), (C) AND (D) OF THE TRUST INDENTURE ACT.

                    SECTION 2.04        Periodic Reports to Guarantee 
          Trustee.  The Guarantor shall provide to the Guarantee Trustee 
          such documents, reports and information as required by Section 
          314 (if any) and the compliance certificate required by Section 
          314 of the Trust Indenture Act in the form, in the manner and 
          at the times required by Section 314 of the Trust Indenture Act.

                    SECTION 2.05        Evidence of Compliance with
          Conditions Precedent.  The Guarantor shall provide to the
          Guarantee Trustee such evidence of compliance with any conditions
          precedent provided for in this Guarantee Agreement as and to the
          extent required by Section 314(c) of the Trust Indenture Act. 
          Any certificate or opinion required to be given by an officer
          pursuant to Section 314(c)(1) of the Trust Indenture Act may be
          given in the form of an Officers' Certificate.

                    SECTION 2.06        Events of Default; Waiver.  The
          Holders of a Majority in liquidation amount of Preferred
          Securities may, by vote, on behalf of all of the Holders, waive
          any past Event of Default and its consequences.  Upon such
          waiver, any such Event of Default shall cease to exist, and any
          Event of Default arising therefrom shall be deemed to have been
          cured, for every purpose of this Guarantee Agreement, but no such
          waiver shall extend to any subsequent or other default or Event
          of Default or impair any right consequent thereon.

                    SECTION 2.07        Event of Default; Notice.

                    (a)  The Guarantee Trustee shall, within 90 days after
          the occurrence of an Event of Default, transmit by mail, first
          class postage prepaid, to the Holders, notices of all Events of
          Default known to the Guarantee Trustee, unless such defaults have
          been cured before the giving of such notice, provided that, the
          Guarantee Trustee shall be protected in withholding such notice
          if and so long as the board of directors, the executive
          committee, or a trust committee of directors or Responsible
          Officers of the Guarantee Trustee in good faith determines that
          the withholding of such notice is in the interests of the
          Holders.

                    (b)  The Guarantee Trustee shall not be deemed to have
          knowledge of any Event of Default unless the Guarantee Trustee
          shall have received written notice, or a Responsible Officer
          charged with the administration of the Trust Agreement shall have
          obtained written notice, of such Event of Default.

                    SECTION 2.08        Conflicting Interests.  The Trust
          Agreement and the Indenture shall be deemed to be specifically
          described in this Guarantee Agreement for the purposes of clause
          (i) of the first proviso contained in Section 310(b) of the Trust
          Indenture Act.


                                     ARTICLE III

                    POWERS, DUTIES AND RIGHTS OF GUARANTEE TRUSTEE

                    SECTION 3.01        Powers and Duties of the Guarantee
          Trustee.

                    (a)  This Guarantee Agreement shall be held by the
          Guarantee Trustee for the benefit of the Holders, and the
          Guarantee Trustee shall not transfer this Guarantee Agreement or
          any rights hereunder to any Person except a Holder exercising his
          or her rights pursuant to Section 5.04 or to a Successor
          Guarantee Trustee on acceptance by such Successor Guarantee
          Trustee of its appointment to act as Successor Guarantee Trustee. 
          The right, title and interest of the Guarantee Trustee shall
          automatically vest in any Successor Guarantee Trustee, and such
          vesting and cessation of title shall be effective whether or not
          conveyancing documents have been executed and delivered pursuant
          to the appointment of such Successor Guarantee Trustee.

                    (b)  The Guarantee Trustee, prior to the occurrence of
          any Event of Default and after the curing of all Events of
          Default that may have occurred, shall undertake to perform only
          such duties as are specifically set forth in this Guarantee
          Agreement, and no implied covenants or obligations shall be read
          into this Guarantee Agreement against the Guarantee Trustee.  In
          case an Event of Default has occurred (that has not been cured or
          waived pursuant to Section 2.06), the Guarantee Trustee shall
          exercise such of the rights and powers vested in it by this
          Guarantee Agreement, and use the same degree of care and skill in
          its exercise thereof, as a prudent person would exercise or use
          under the circumstances in the conduct of his or her own affairs.

                    (c)  No provision of this Guarantee Agreement shall be
          construed to relieve the Guarantee Trustee from liability for its
          own negligent action, its own negligent failure to act, or its
          own willful misconduct, except that:

                          (i)  prior to the occurrence of any Event of
                    Default and after the curing or waiving of all such
                    Events of Default that may have occurred:

                              (A)  the duties and obligations of the
                         Guarantee Trustee shall be determined solely by
                         the express provisions of this Guarantee
                         Agreement, and the Guarantee Trustee shall not be
                         liable except for the performance of such duties
                         and obligations as are specifically set forth in
                         this Guarantee Agreement; and

                              (B)  in the absence of bad faith on the part
                         of the Guarantee Trustee, the Guarantee Trustee
                         may conclusively rely, as to the truth of the
                         statements and the correctness of the opinions
                         expressed therein, upon any certificates or
                         opinions furnished to the Guarantee Trustee and
                         conforming to the requirements of this Guarantee
                         Agreement; but in the case of any such
                         certificates or opinions that by any provision
                         hereof are specifically required to be furnished
                         to the Guarantee Trustee, the Guarantee Trustee
                         shall be under a duty to examine the same to
                         determine whether or not they conform to the
                         requirements of this Guarantee Agreement;

                         (ii)  the Guarantee Trustee shall not be liable
                    for any error of judgment made in good faith by a
                    Responsible Officer of the Guarantee Trustee, unless it
                    shall be proved that the Guarantee Trustee or such
                    Responsible Officer was negligent in ascertaining the
                    pertinent facts upon which such judgment was made; 

                          (iii)  the Guarantee Trustee shall not be liable
                    with respect to any action taken or omitted to be taken
                    by it in good faith in accordance with the direction of
                    the Holders of a Majority in liquidation amount of the
                    Preferred Securities relating to the time, method and
                    place of conducting any proceeding for any remedy
                    available to the Guarantee Trustee, or exercising any
                    trust or power conferred upon the Guarantee Trustee
                    under this Guarantee Agreement; and

                           (iv)  no provision of this Guarantee Agreement
                    shall require the Guarantee Trustee to expend or risk
                    its own funds or otherwise incur personal financial
                    liability in the performance of any of its duties or in
                    the exercise of any of its rights or powers, if the
                    Guarantee Trustee shall have reasonable grounds for
                    believing that the repayment of such funds or liability
                    is not reasonably assured to it under the terms of this
                    Guarantee Agreement or adequate indemnity against such
                    risk or liability is not reasonably assured to it.

                    SECTION 3.02        Certain Rights of Guarantee
          Trustee.

                    (a)  Subject to the provisions of Section 3.01:

                        (i)  the Guarantee Trustee may rely and shall be
                    fully protected in acting or refraining from acting
                    upon any resolution, certificate, statement,
                    instrument, opinion, report, notice, request,
                    direction, consent, order, bond, debenture, note, other
                    evidence of indebtedness or other paper or document
                    reasonably believed by it to be genuine and to have
                    been signed, sent or presented by the proper party or
                    parties;

                       (ii)  any direction or act of the Guarantor
                    contemplated by this Guarantee Agreement shall be
                    sufficiently evidenced by an Officers' Certificate;

                      (iii)  whenever, in the administration of this
                    Guarantee Agreement, the Guarantee Trustee shall deem
                    it desirable that a matter be proved or established
                    before taking, suffering or omitting any action
                    hereunder, the Guarantee Trustee (unless other evidence
                    is herein specifically prescribed) may, in the absence
                    of bad faith on its part, request and rely upon an
                    Officers' Certificate which, upon receipt of such
                    request, shall be promptly delivered by the Guarantor;

                       (iv)  the Guarantee Trustee may consult with counsel
                    of its choice, and the written advice or opinion of
                    such counsel with respect to legal matters shall be
                    full and complete authorization and protection in
                    respect of any action taken, suffered or omitted by it
                    hereunder in good faith and in accordance with such
                    advice or opinion; such counsel may be counsel to the
                    Guarantor or any of its Affiliates and may include any
                    of its employees; the Guarantee Trustee shall have the
                    right at any time to seek instructions concerning the
                    administration of this Guarantee Agreement from any
                    court of competent jurisdiction;

                        (v)  the Guarantee Trustee shall be under no
                    obligation to exercise any of the rights or powers
                    vested in it by this Guarantee Agreement at the request
                    or direction of any Holder, unless such Holder shall
                    have provided to the Guarantee Trustee such adequate
                    security and indemnity as would satisfy a reasonable
                    person in the position of the Guarantee Trustee,
                    against the costs, expenses (including attorneys' fees
                    and expenses) and liabilities that might be incurred by
                    it in complying with such request or direction,
                    including such reasonable advances as may be requested
                    by the Guarantee Trustee; provided that, nothing
                    contained in this Section 3.02(a)(v) shall be taken to
                    relieve the Guarantee Trustee, upon the occurrence of
                    an Event of Default, of its obligation to exercise the
                    rights and powers vested in it by this Guarantee
                    Agreement;

                       (vi)  the Guarantee Trustee shall not be bound to
                    make any investigation into the facts or matters stated
                    in any resolution, certificate, statement, instrument,
                    opinion, report, notice, request, direction, consent,
                    order, bond, debenture, note, other evidence of
                    indebtedness or other paper or document reasonably
                    believed by it to be genuine, but the Guarantee
                    Trustee, in its discretion, may make such further
                    inquiry or investigation into such facts or matters as
                    it may see fit;

                      (vii)  the Guarantee Trustee may execute any of the
                    trusts or powers hereunder or perform any duties
                    hereunder either directly or by or through agents or
                    attorneys, and the Guarantee Trustee shall not be
                    responsible for any misconduct or negligence on the
                    part of any agent or attorney appointed with due care
                    by it hereunder;

                     (viii)  whenever in the administration of this
                    Guarantee Agreement the Guarantee Trustee shall deem it
                    desirable to receive instructions with respect to
                    enforcing any remedy or right or taking any other
                    action hereunder, the Guarantee Trustee (1) may request
                    instructions from the Holders, (2) may refrain from
                    enforcing such remedy or right or taking such other
                    action until such instructions are received, and (3)
                    shall be protected in acting in accordance with such
                    instructions; and 

                       (ix)  the Guarantee Trustee shall not be liable for
                    any action taken, suffered or omitted to be taken by it
                    in good faith and reasonably believed by it to be
                    authorized or within the discretion or rights or powers
                    conferred upon it by this Guarantee.

                    (b)  No provision of this Guarantee Agreement shall be
          deemed to impose any duty or obligation on the Guarantee Trustee
          to perform any act or acts or exercise any right, power, duty or
          obligation conferred or imposed on it in any jurisdiction in
          which it shall be illegal, or in which the Guarantee Trustee
          shall be unqualified or incompetent in accordance with applicable
          law, to perform any such act or acts or to exercise any such
          right, power, duty or obligation.  No permissive power or
          authority available to the Guarantee Trustee shall be construed
          to be a duty.


                                      ARTICLE IV

                                  GUARANTEE TRUSTEE

                    SECTION 4.01        Guarantee Trustee; Eligibility.

                    (a)  There shall at all times be a Guarantee Trustee
               which shall:

                         (i)  not be an Affiliate of the Guarantor; and

                         (ii)  be a corporation organized and doing
                    business under the laws of the United States of America
                    or any State or Territory thereof or of the District of
                    Columbia, or a corporation or Person permitted by the
                    Securities and Exchange Commission to act as an
                    institutional trustee under the Trust Indenture Act,
                    authorized under such laws to exercise corporate trust
                    powers, having a combined capital and surplus of at
                    least 50 million U.S. dollars ($50,000,000), and
                    subject to supervision or examination by Federal,
                    State, Territorial or District of Columbia authority. 
                    If such corporation publishes reports of condition at
                    least annually, pursuant to law or to the requirements
                    of the supervising or examining authority referred to
                    above, then, for the purposes of this Section
                    4.01(a)(ii), the combined capital and surplus of such
                    corporation shall be deemed to be its combined capital
                    and surplus as set forth in its most recent report of
                    condition so published.

                    (b)  If at any time the Guarantee Trustee shall cease
          to be eligible to so act under Section 4.01(a), the Guarantee
          Trustee shall immediately resign in the manner and with the
          effect set out in Section 4.03(c).

                    (c)  If the Guarantee Trustee has or shall acquire any
          "conflicting interest" within the meaning of Section 310(b) of
          the Trust Indenture Act, the Guarantee Trustee and Guarantor
          shall in all respects comply with the provisions of Section
          310(b) of the Trust Indenture Act.

                    SECTION 4.02        Compensation and Reimbursement.

                    The Guarantor agrees:

                    (a)  to pay the Guarantee Trustee from time to time
          such reasonable compensation as the Guarantor and the Guarantee
          Trustee shall from time to time agree in writing for all services
          rendered by it hereunder (which compensation shall not be limited
          by any provision of law in regard to the compensation of a
          trustee of an express trust);

                    (b)  except as otherwise expressly provided herein, to
          reimburse the Guarantee Trustee upon its request for all
          reasonable expenses, disbursements and advances incurred or made
          by the Guarantee Trustee in accordance with the provisions of
          this Guarantee (including the reasonable compensation and
          expenses of its agents and counsel), except any such expense,
          disbursement or advance as may be attributable to its negligence
          or bad faith; and

                    (c)  to indemnify each of the Guarantee Trustee and any
          predecessor Guarantee Trustee for, and to hold it harmless from
          and against, any and all loss, damage, claim, liability or
          expense, including taxes (other than taxes based upon the income
          of the Guarantee Trustee) incurred without negligence or bad
          faith on its part, arising out of or in connection with the
          acceptance of the administration of this Guarantee Agreement,
          including the costs and expenses of defending itself against any
          claim or liability in connection with the exercise or performance
          of any its powers or duties hereunder.

                    As security for the performance of the obligations of
          the Guarantor under this Section, the Guarantee Trustee shall
          have a lien prior to the Preferred Securities upon all the
          property and funds held or collected by the Guarantee Trustee as
          such, except funds held in trust for the payment of principal of,
          and premium (if any) or interest on, particular obligations of
          the Guarantor under this Guarantee Agreement.

                    The provisions of this Section shall survive the
          termination of this Guarantee Agreement.

                    SECTION 4.03        Appointment, Removal and
          Resignation of Guarantee Trustee.

                    (a)  Subject to Section 4.03(b), unless an Event of
          Default shall have occurred and be continuing, the Guarantee
          Trustee may be appointed or removed without cause at any time by
          the Guarantor.

                    (b)  The Guarantee Trustee shall not be removed until a
          Successor Guarantee Trustee has been appointed and has accepted
          such appointment by written instrument executed by such Successor
          Guarantee Trustee and delivered to the Guarantor.

                    (c)  The Guarantee Trustee appointed to office shall
          hold office until a Successor Guarantee Trustee shall have been
          appointed or until its removal or resignation.  The Guarantee
          Trustee may resign from office (without need for prior or
          subsequent accounting) by an instrument in writing executed by
          the Guarantee Trustee and delivered to the Guarantor, which
          resignation shall not take effect until a Successor Guarantee
          Trustee has been appointed and has accepted such appointment by
          instrument in writing executed by such Successor Guarantee
          Trustee and delivered to the Guarantor and the resigning
          Guarantee Trustee.

                    (d)  If no Successor Guarantee Trustee shall have been
          appointed and accepted appointment as provided in this Section
          4.03 within 60 days after delivery to the Guarantor of an
          instrument of resignation, the resigning Guarantee Trustee may
          petition any court of competent jurisdiction for appointment of a
          Successor Guarantee Trustee.  Such court may thereupon, after
          prescribing such notice, if any, as it may deem proper, appoint a
          Successor Guarantee Trustee.

                    (e)  The Guarantor shall give notice of each
          resignation and each removal of the Guarantee Trustee and each
          appointment of a successor Guarantee Trustee to all Holders in
          the manner provided in Section 8.03 hereof.  Each notice shall
          include the name of the successor Guarantee Trustee and the
          address of its Corporate Trust Office.


                                      ARTICLE V

                                      GUARANTEE

                    SECTION 5.01        Guarantee.  The Guarantor
          irrevocably and unconditionally agrees to pay in full to the
          Holders the Guarantee Payments (without duplication of amounts
          theretofore paid by the Issuer), as and when due, regardless of
          any defense, right of set-off or counterclaim which the Issuer
          may have or assert.  The Guarantor's obligation to make a
          Guarantee Payment may be satisfied by direct payment of the
          required amounts by the Guarantor to the Holders or by causing
          the Issuer to pay such amounts to the Holders.

                    SECTION 5.02        Waiver of Notice and Demand.  The
          Guarantor hereby waives notice of acceptance of this Guarantee
          Agreement and of any liability to which it applies or may apply,
          presentment, demand for payment, any right to require a
          proceeding first against the Issuer or any other Person before
          proceeding against the Guarantor, protest, notice of nonpayment,
          notice of dishonor, notice of redemption and all other notices
          and demands.

                    SECTION 5.03        Obligations Not Affected.  The
          obligation of the Guarantor to make the Guarantee Payments under
          this Guarantee Agreement shall in no way be affected or impaired
          by reason of the happening from time to time of any of the
          following:

                    (a)  the release or waiver, by operation of law or
               otherwise, of the performance or observance by the Issuer of
               any express or implied agreement, covenant, term or
               condition relating to the Preferred Securities to be
               performed or observed by the Issuer;

                    (b)  the extension of time for the payment by the
               Issuer of all or any portion of the Distributions,
               Redemption Price, Liquidation Distribution or any other sums
               payable under the terms of the Preferred Securities or the
               extension of time for the performance of any other
               obligation under, arising out of, or in connection with, the
               Preferred Securities (other than an extension of time for
               payment of Distributions, Redemption Price, Liquidation
               Distribution or other sum payable that results from the
               extension of any interest payment period on the Debentures
               permitted by the Indenture);

                    (c)  any failure, omission, delay or lack of diligence
               on the part of the Holders to enforce, assert or exercise
               any right, privilege, power or remedy conferred on the
               Holders pursuant to the terms of the Preferred Securities,
               or any action on the part of the Issuer granting indulgence
               or extension of any kind;

                    (d)  the voluntary or involuntary liquidation,
               dissolution, sale of any collateral, receivership,
               insolvency, bankruptcy, assignment for the benefit of
               creditors, reorganization, arrangement, composition or
               readjustment of debt of, or other similar proceedings
               affecting, the Issuer or any of the assets of the Issuer;

                    (e)  any invalidity of, or defect or deficiency in, the
               Preferred Securities;

                    (f)  the settlement or compromise of any obligation
               guaranteed hereby or hereby incurred; or 

                    (g)  any other circumstance whatsoever that might
               otherwise constitute a legal or equitable discharge or
               defense of a guarantor, it being the intent of this Section
               5.03 that the obligations of the Guarantor hereunder shall
               be absolute and unconditional under any and all
               circumstances.

          There shall be no obligation of the Holders to give notice to, or
          obtain consent of, the Guarantor with respect to the happening of
          any of the foregoing.

                    SECTION 5.04        Rights of Holders.  The Guarantor
          expressly acknowledges that: (i) this Guarantee Agreement will be
          deposited with the Guarantee Trustee to be held for the benefit
          of the Holders; (ii) the Guarantee Trustee has the right to
          enforce this Guarantee Agreement on behalf of the Holders; (iii)
          the Holders of a Majority in liquidation amount of the Preferred
          Securities have the right to direct the time, method and place of
          conducting any proceeding for any remedy available to the
          Guarantee Trustee in respect of this Guarantee Agreement or
          exercising any trust or power conferred upon the Guarantee
          Trustee under this Guarantee Agreement; and (iv) any Holder may
          institute a legal proceeding directly against the Guarantor to
          enforce its rights under this Guarantee Agreement without first
          instituting a legal proceeding against the Issuer or any other
          person or entity.

                    SECTION 5.05        Guarantee of Payment.  This
          Guarantee Agreement creates a guarantee of payment and not of
          collection.  This Guarantee Agreement will not be discharged
          except by payment of the Guarantee Payments in full (without
          duplication).

                    SECTION 5.06        Subrogation.  The Guarantor shall
          be subrogated to all (if any) rights of the Holders against the
          Issuer in respect of any amounts paid to the Holders by the
          Guarantor under this Guarantee Agreement; provided, however, that
          the Guarantor shall not (except to the extent required by
          mandatory provisions of law) be entitled to enforce or exercise
          any rights which it may acquire by way of subrogation or any
          indemnity, reimbursement or other agreement, in all cases as a
          result of payment under this Guarantee Agreement, if, at the time
          of any such payment, any amounts of Guarantee Payments are due
          and unpaid under this Guarantee Agreement.  If any amount shall
          be paid to the Guarantor in violation of the preceding sentence,
          the Guarantor agrees to hold such amount in trust for the Holders
          and to pay over such amount to the Holders.

                    SECTION 5.07        Independent Obligations.  The
          Guarantor acknowledges that its obligations hereunder are
          independent of the obligations of the Issuer with respect to the
          Preferred Securities and that the Guarantor shall be liable as
          principal and as debtor hereunder to make Guarantee Payments
          pursuant to the terms of this Guarantee Agreement notwithstanding
          the occurrence of any event referred to in subsections (a)
          through (g), inclusive, of Section 5.03.


                                      ARTICLE VI

                                    SUBORDINATION

                    SECTION 6.01        Subordination.  This Guarantee
          Agreement will constitute an unsecured obligation of the
          Guarantor and will rank (i) subordinate and junior in right of
          payment to all other liabilities of the Guarantor, including the
          Debentures, except those made pari passu or subordinate by their
          terms, (ii) pari passu with the most senior preferred or
          preference stock now or hereafter issued by the Guarantor and
          with any guarantee now or hereafter entered into by the Guarantor
          in respect of any preferred or preference stock of any Affiliate
          of the Guarantor, and (iii) senior to all common stock of the
          Guarantor.  Nothing in this Section 6.01 shall apply to claims
          of, or payments to, the Guarantee Trustee under or pursuant to
          Section 4.02 hereof.


                                     ARTICLE VII

                                     TERMINATION

                    SECTION 7.01        Termination.  This Guarantee
          Agreement shall terminate and be of no further force and effect
          upon: (i) full payment of the Redemption Price of all Preferred
          Securities, and all accrued and unpaid Distributions to the date
          of redemption, (ii) the distribution of Debentures to Holders in
          exchange for all of the Preferred Securities or (iii) full
          payment of the amounts payable in accordance with the Trust
          Agreement upon liquidation of the Issuer.  Notwithstanding the
          foregoing, this Guarantee Agreement will continue to be effective
          or will be reinstated, as the case may be, if at any time any
          Holder must restore payment of any sums paid with respect to
          Preferred Securities or under this Guarantee Agreement.


                                     ARTICLE VIII

                                    MISCELLANEOUS

                    SECTION 8.01        Successors and Assigns.  All
          guarantees and agreements contained in this Guarantee Agreement
          shall bind the successors, assigns, receivers, trustees and
          representatives of the Guarantor and shall inure to the benefit
          of the Holders of the Preferred Securities then outstanding. 
          Except in connection with a consolidation, merger or sale
          involving the Guarantor that is permitted under Article Eleven of
          the Indenture, the Guarantor shall not assign its obligations
          hereunder.

                    SECTION 8.02        Amendments.  This Guarantee
          Agreement may be amended only by an instrument in writing entered
          into by the Guarantor and the Guarantee Trustee.  Except with
          respect to any changes which do not materially adversely affect
          the rights of Holders (in which case no consent of Holders will
          be required), this Guarantee Agreement may only be amended with
          the prior approval of the Holders of not less than 66 2/3% in
          aggregate liquidation amount of all the outstanding Preferred
          Securities.  The provisions of Article VI of the Trust Agreement
          concerning meetings of Holders shall apply to the giving of such
          approval.  Nothing herein contained shall be deemed to require
          that the Guarantee Trustee enter into any amendment of this
          Guarantee Agreement.

                    SECTION 8.03        Notices.  Any notice, request or
          other communication required or permitted to be given hereunder
          shall be in writing, duly signed by the party giving such notice,
          and delivered, telecopied or mailed by first class mail as
          follows:

                    (a)  if given to the Guarantor, to the address set
               forth below or such other address as the Guarantor may give
               notice of to the Holders of the Preferred Securities:

                              Minnesota Power & Light Company
                              30 West Superior Street
                              Duluth, Minnesota  55802
                              Facsimile No:  
                              Attention:  

                    (b)  if given to the Issuer, in care of the
               Administrative Trustees, at the Issuer's (and the
               Administrative Trustee's) address set forth below or such
               other address as the Administrative Trustees on behalf of
               the Issuer may give notice of to the Holders:

                              MP&L Capital I
                              c/o Minnesota Power & Light Company
                              30 West Superior Street
                              Duluth, Minnesota  55802
                              Facsimile No:  
                              Attention:  Administrative Trustees

                    (c)  if given to the Guarantee Trustee, to the address
               set forth below or such other address as the Guarantee
               Trustee may give notice of to the Holders of the Preferred
               Securities:

                              The Bank of New York
                              101 Barclay Street
                              New York, New York 10286

                              Facsimile No: (212) 815-5915
                              Attention: Corporate Trust Trustee
                                           Administration

                    (d)  if given to any Holder, at the address set forth
               on the books and records of the Issuer.

                    All notices hereunder shall be deemed to have been
          given when received in person, telecopied with receipt confirmed,
          or mailed by first class mail, postage prepaid except that if a
          notice or other document is refused delivery or cannot be
          delivered because of a changed address of which no notice was
          given, such notice or other document shall be deemed to have been
          delivered on the date of such refusal or inability to deliver.

                    SECTION 8.04        Benefit.  This Guarantee Agreement
          is solely for the benefit of the Holders and, subject to Section
          3.01(a), is not separately transferable from the Preferred
          Securities.
          
                    SECTION 8.05        Interpretation.  In this Guarantee
          Agreement, unless the context otherwise requires: 

                    (a)  Capitalized terms used in this Guarantee Agreement
               but not defined in the preamble hereto have the respective
               meanings assigned to them in Section 1.01;

                    (b)  a term defined anywhere in this Guarantee
               Agreement has the same meaning throughout;

                    (c)  all references to "the Guarantee Agreement" or
               "this Guarantee Agreement" are to this Guarantee Agreement
               as modified, supplemented or amended from time to time;

                    (d)  all references in this Guarantee Agreement to
               Articles and Sections are to Articles and Sections of this
               Guarantee Agreement unless otherwise specified;

                    (e)  a term defined in the Trust Indenture Act has the
               same meaning when used in this Guarantee Agreement unless
               otherwise defined in this Guarantee Agreement or unless the
               context otherwise requires;

                    (f)  a reference to the singular includes the plural
               and vice versa; and

                    (g)  the masculine, feminine or neuter genders used
               herein shall include the masculine, feminine and neuter
               genders.

                    SECTION 8.06        Governing Law.  This Guarantee
          Agreement shall be governed by and construed and interpreted in
          accordance with the laws of the State of New York.

                    This instrument may be executed in any number of
          counterparts, each of which so executed shall be deemed to be an
          original, but all such counterparts shall together constitute but
          one and the same instrument.

          

                    THIS GUARANTEE AGREEMENT is executed as of the day and
          year first above written.


                                       Minnesota Power & Light Company


                                       By:________________________
                                           Name:
                                           Title:



                                        The Bank of New York,
                                          as Guarantee Trustee


                                        By: ______________________
                                             Name:
                                             Title: