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                                                                    Exhibit 4(b)

                                ADESA CORPORATION

                           OFFICER'S CERTIFICATE 2-D-2

         William T.  Stackhouse,  Chief Financial  Officer of ADESA  Corporation
(the "Company"),  pursuant to the authority  granted in the Board Resolutions of
the  Company  dated  as of  March  10,  2000,  and  Sections  201 and 301 of the
Indenture  defined herein,  in his capacity as such, does hereby certify for and
on behalf of the  Company  to The Bank of New York (the  "Trustee"),  as Trustee
under the Indenture of the Company (For Unsecured Debt  Securities)  dated as of
May 15, 1996 (as supplemented, the "Indenture"), that:

1.       The  Securities  of the second  series to be issued under the Indenture
         shall be  designated  "8.10%  Senior  Notes,  Series B, Due 2010"  (the
         "Securities of the Second  Series").  The term  "Guarantor"  shall mean
         Minnesota Power, Inc., its successors and assigns. The term "Guarantee"
         shall  mean  the  Guarantee  described  in  paragraph  13  hereof.  All
         capitalized terms used in this certificate which are not defined herein
         but are defined in the  Indenture  shall have the meanings set forth in
         the Indenture;

2.       The Securities of the Second Series shall be limited in aggregate
         principal  amount to  $35,000,000  at any time  Outstanding,  except as
         contemplated in Section 301(b) of the Indenture;

3.       The Securities of the Second Series shall mature and the principal
         shall be due and payable  together with all accrued and unpaid interest
         thereon on March 30, 2010;

4.       The  Securities  of the Second  Series shall bear  interest  from,  and
         including,  March 30,  2000,  at the rate of 8.10%  per  annum  payable
         semi-annually  on March 30 and  September  30 of each  year  (each,  an
         "Interest Payment Date") commencing  September 30, 2000;  PROVIDED that
         such rate of  interest  shall be 10.10% per annum  with  respect to any
         days during which an Event of Default with respect to the Securities of
         the Second Series shall exist and be continuing. The amount of interest
         payable  for any such period will be computed on the basis of a 360-day
         year of twelve  30-day  months and for any period  shorter  than a full
         month,  on the  basis of the  actual  number  of days  elapsed  in such
         period.  Interest on the  Securities  of the Second  Series will accrue
         from, and including,  the date of original  issuance and will accrue to
         the first Interest  Payment Date, and thereafter  will accrue from, and
         including,  the last Interest  Payment Date to which  interest has been
         paid or duly provided for. 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 such Interest Payment Date;

5.       Each installment of interest on a Security of the Second Series shall
         be payable to the Person in whose name such  Security is  registered at
         the  close of  business  on the date  fifteen  (15)  days  prior to the
         relevant  Interest  Payment Date (the "Regular Record Date") or if such
         date is not a Business  Day,  the next  succeeding  Business  Day.  The
         Company  shall  not be  required  to  execute  or to  provide  for  the
         registration  of  transfer of or the  exchange  of any  Security of the
         Second  Series  during a period of 15 days next  preceding any Interest
         Payment  Date for such  Series.  Any  installment  of  interest  on the
         Securities  of the Second Series not  punctually  paid or duly provided
         for  shall  forthwith  cease  to be  payable  to the  Holders  of  such
         Securities of the Second Series on such Regular  Record Date and may be
         paid to the Persons in whose name the  Securities  of the

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         Second  Series are  registered  at the close of  business  on a Special
         Record  Date  to be  fixed  by the  Trustee  for  the  payment  of such
         Defaulted  Interest.  Notice of such  Defaulted  Interest  and  Special
         Record  Date  shall be given to the  Holders of the  Securities  of the
         Second Series not less than 10 days prior to such Special  Record Date,
         or may be paid at any time in any other lawful manner not  inconsistent
         with  the  requirements  of  any  securities   exchange  on  which  the
         Securities of the Second Series may be listed,  and upon such notice as
         may be required  by such  exchange,  all as more fully  provided in the
         Indenture;

6.       The principal, premium, if any, and each installment of interest on the
         Securities of the Second Series shall be payable as provided in Exhibit
         A.  Registration and registration of transfers and exchanges in respect
         of the Securities of the Second Series may be effected at the office or
         agency of the  Company in The City of New York.  Notices and demands to
         or upon the Company in respect of the  Securities  of the Second Series
         may be served at the office or agency of the Company in The City of New
         York.  The Corporate  Trust Office of the Trustee will initially be the
         agency of the Company for such service of notices and demands,  and the
         Company hereby appoints the Trustee as its agent for all such purposes;
         provided,  however,  that the Company reserves the right to change,  by
         one or more  Officer's  Certificates,  any such  office or agency.  The
         Company will  initially be the Security  Registrar and the Paying Agent
         for the Securities of the Second Series;

7.       The Securities of the Second Series will be redeemable as provided in
         the form set forth in Exhibit A hereto,  upon not less than 30 nor more
         than 60 days'  notice  given  to the  Holders  thereof.  In case of any
         redemption  at the election of the Company of all of the  Securities of
         the Second  Series,  the Company  shall,  at least 45 days prior to the
         Redemption  Date fixed by the Company (unless a shorter notice shall be
         satisfactory  to the  Trustee),  notify the  Trustee in writing of such
         Redemption  Date.  In case of any  redemption  at the  election  of the
         Company of less than all the  Securities  of such  series,  the Company
         shall,  at least  45 days  prior to the  Redemption  Date  fixed by the
         Company (unless a shorter notice shall be satisfactory to the Trustee),
         notify  the  Trustee  in  writing  of such  Redemption  Date and of the
         principal  amount  of  Securities  of such  series to be  redeemed  and
         deliver to the Trustee an Officer's Certificate stating that no default
         in  payment  of  interest  or  Event of  Default  with  respect  to the
         Securities of such series has occurred (or, if such an Event of Default
         shall have occurred,  that the same has been cured or waived).  In case
         of any partial  redemption of the Securities of the Second Series,  the
         principal  amount  to be  redeemed  shall  be  prorated  as  nearly  as
         practicable  among the  Holders of the  Outstanding  Securities  of the
         Second Series  except that the portion of the principal  amount of each
         Outstanding  Security of the Second Series to be redeemed  shall always
         be $1,000 or an integral multiple thereof;

8.       Each Security of the Second Series shall bear the non-registration
         legend in substantially the form set forth in Exhibit A hereto,  unless
         otherwise  agreed by the  Company,  such  agreement  to be confirmed in
         writing to the Trustee. Nothing in the Indenture, the Securities of the
         Second  Series or this  certificate  shall be  construed to require the
         Company to  register  any  Securities  of the Second  Series  under the
         Securities  Act of 1933,  as amended,  (the  "Securities  Act")  unless
         otherwise expressly agreed by the Company,  confirmed in writing to the
         Trustee,  or to make any  transfer of such  Securities  in violation of
         applicable  law. In  connection  with any transfer of Securities of the
         Second Series,  the transferring  Holders and their  transferees  shall
         provide the Company and the Trustee  with such  certificates  and other
         information  as the  Company  or the  Trustee  may  reasonably  request
         regarding the  compliance of such transfer with the  Securities Act and
         any applicable  state securities laws or any exemption  therefrom,  the
         validity,  legality and due  authorization  of any such  transfer,  the
         eligibility  of the  transferee  to receive such Security and any other
         facts and circumstances related to such transfer;  and the Trustee, the
         Security  Registrar  and

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         the Company  shall be under no duty to inquire into,  may  conclusively
         presume the  correctness  of, and shall be fully  protected  in relying
         upon such opinions,  certificates and other  information  received from
         the Holders and any transferees of any Securities of the Second Series;

9.       No service  charge  shall be made for the  registration  of transfer or
         exchange of the  Securities of the Second  Series;  provided,  however,
         that the Company may require  payment of a sum  sufficient to cover any
         tax or other governmental charge that may be imposed in connection with
         the exchange or transfer;

10.      The Company additionally covenants that, so long as any Securities of
         the Second Series remain Outstanding, it will:

         A.       keep proper books of record and account in accordance with
                  generally accepted accounting principles;

         B.       pay all applicable taxes, assessments and governmental charges
                  imposed  upon  it or any of its  properties  or  assets  or in
                  respect of any of its  franchises,  business income or profits
                  and  comply  with all  applicable  statutes,  regulations  and
                  orders of governmental bodies relating to taxes except for any
                  tax the payment of which, or statutes,  regulations and orders
                  the compliance with which, in each case, is being contested in
                  good  faith and by  appropriate  means and for which  adequate
                  reserves  have been  provided  or with  respect to which there
                  would not  reasonably  be  expected  to be a material  adverse
                  effect on the financial condition of the Company;

         C.       carry and  maintain in full force and effect at all times with
                  fiscally sound and reputable  insurers  insurance against such
                  risks as the  Company  deems  reasonable  and  prudent  in the
                  circumstances;   provided   that  such   insurance   shall  be
                  comparable  to insurance  carried by, or otherwise  maintained
                  by,  comparable  companies  similarly  situated to the Company
                  carrying on the same types of businesses;

         D.       comply with the requirements of all applicable laws, rules,
                  regulations  and  orders of any  governmental  authority,  the
                  noncompliance with which would materially adversely affect the
                  business,  condition (financial or other), assets,  properties
                  or operations of the Company taken as a whole; and

         E.       give prompt written notice to the Holders of its acceptance of
                  the  appointment  by the Trustee of any  Authenticating  Agent
                  (such   notice  to  include  the  name  and  address  of  such
                  Authenticating  Agent) as  contemplated  by Section 915 of the
                  Indenture.

11.      So long as any Securities of the Second Series remain Outstanding,  the
         following shall constitute additional Events of Default with respect to
         such series:

         (a)      At any time prior to the payment in full of all amounts due
                  under the Securities of the Second  Series,  the Company shall
                  (A)  fail  to  pay  aggregate   Indebtedness  (as  hereinafter
                  defined)  in excess of the greater of (i) $15 million and (ii)
                  5%  of  the  total  assets  of  the  Company  (whether  as  to
                  principal,  interest or  premium)  when due, or (B) breach any
                  covenant with respect to aggregate  Indebtedness  in excess of
                  the greater of (i) $15 million and (ii) 5% of the total assets
                  of the Company (whether as to principal, interest or premium),
                  and such failure or breach  shall  continue  after  applicable
                  grace  periods   specified  in  the  agreement  or  instrument
                  relating to such  Indebtedness,  if the effect of such failure
                  or breach is to accelerate the maturity of such  Indebtedness,
                  and, in such

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                  case,  the  Company  shall  have  failed to cure (or  obtain a
                  waiver of) such  failure,  breach or  default  within ten days
                  after the expiration of such grace period has occurred;

         (b)      At any time prior to the  payment in full of all  amounts  due
                  under the Securities of the Second Series, the Guarantor shall
                  fail to pay  aggregate  Indebtedness  in excess of $25 million
                  (whether as to  principal,  interest or premium) when due, and
                  such failure shall  continue  after  applicable  grace periods
                  specified  in the  agreement  or  instrument  relating to such
                  Indebtedness,  if the effect of such failure is to  accelerate
                  the  maturity of such  Indebtedness,  and,  in such case,  the
                  Guarantor  shall  have  failed to cure (or obtain a waiver of)
                  such failure or default with ten days after the  expiration of
                  such grace period has occurred;

                  INDEBTEDNESS,  as used in this  certificate,  shall mean, with
                  respect  to a  Person  (as  defined  in  the  Indenture),  all
                  obligations  (other  than  non-recourse  obligations)  of,  or
                  guaranteed  or assumed by, such Person for  borrowed  money or
                  obligations  under  leases  of  personal  property  which  are
                  required by  generally  accepted  accounting  practices  to be
                  capitalized on the balance sheet of such Person.

         (c)      The entry by a court having jurisdiction in the premises of

                  (i)      a decree  or  order  for  relief  in  respect  of the
                           Guarantor in an involuntary  case or proceeding under
                           any   applicable   Federal   or   state   bankruptcy,
                           insolvency, reorganization or other similar law or

                  (ii)     a decree or order  adjudging the Guarantor a bankrupt
                           or  insolvent,  or  approving  as  properly  filed  a
                           petition  by one  or  more  persons  other  than  the
                           Guarantor   seeking   reorganization,    arrangement,
                           adjustment  or  composition  of or in  respect of the
                           Guarantor  under  any  applicable  Federal  or  state
                           bankruptcy,   insolvency,   reorganization  or  other
                           similar law, or  appointing  a  custodian,  receiver,
                           liquidator,  assignee, trustee, sequestrator or other
                           similar   official  for  the  Guarantor  or  for  any
                           substantial  part of its  property,  or ordering  the
                           winding up or  liquidation  of its  affairs,  and any
                           such  decree  or order for  relief or any such  other
                           decree or order shall have  remained  unstayed and in
                           effect for a period of 90 consecutive days.

         (d)      The commencement by the Guarantor of a voluntary case or
                  proceeding under any applicable  Federal or state  bankruptcy,
                  insolvency,  reorganization  or  other  similar  law or of any
                  other case or  proceeding  to be  adjudicated  a  bankrupt  or
                  insolvent,  or the  consent  by it to the entry of a decree or
                  order for  relief in  respect  of the  Guarantor  in a case or
                  other  similar  proceeding  or  to  the  commencement  of  any
                  bankruptcy or insolvency  case or proceeding  against it under
                  any  applicable  Federal or state law or the filing by it of a
                  petition or answer or consent seeking reorganization or relief
                  under any applicable Federal or state bankruptcy,  insolvency,
                  reorganization  or other  similar law, or the consent by it to
                  the filing of such petition or to the appointment of or taking
                  possession  by a custodian,  receiver,  liquidator,  assignee,
                  trustee,  sequestrator or similar official of the Guarantor or
                  of any substantial  part of its property,  or the making by it
                  of  an  assignment  for  the  benefit  of  creditors,  or  the
                  admission  by it in writing of its  inability to pay its debts
                  as they become due, or the authorization of such action by the
                  Guarantor's board of directors;

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         (e)      Failure to perform or breach of any covenant or warranty of
                  the  Guarantor in the  Guarantee for a period of 60 days after
                  there has been given,  by registered or certified mail, to the
                  Guarantor by the Trustee,  or to the Guarantor and the Trustee
                  by the  Holders  of at least  25% in  principal  amount of the
                  Outstanding  Securities of the Second Series, a written notice
                  specifying  such  default  or breach  and  requiring  it to be
                  remedied  and  stating  that  such  notice  is  a  "Notice  of
                  Guarantor  Default"  hereunder,  unless  the  Trustee,  or the
                  Trustee and the Holders of a principal amount of Securities of
                  the  Second  Series  not less  than the  principal  amount  of
                  Securities the Holders of which gave such notice,  as the case
                  may be,  shall agree in writing to an extension of such period
                  prior to its expiration;  provided, however, that the Trustee,
                  or the  Trustee and the  Holders of such  principal  amount of
                  Securities of the Second Series,  as the case may be, shall be
                  deemed  to have  agreed  to an  extension  of such  period  if
                  corrective  action is initiated by the  Guarantor  within such
                  period and is being diligently  pursued.  On any date that the
                  principal  financial officer,  the principal executive officer
                  or the principal  accounting  officer of the  Guarantor  shall
                  obtain  actual  knowledge  that the  Guarantor  has  failed to
                  perform or breached any covenant or warranty of the  Guarantor
                  in the  Guarantee  (and  without  limiting  the  rights of the
                  Trustee  or  the  Holders  if an  actual,  written  Notice  of
                  Guarantor  Default shall have been  delivered),  the Guarantor
                  shall  be  deemed  to have  received  on such  date a  written
                  "Notice  of  Guarantor  Default"  specifying  such  failure or
                  breach and requiring it to be remedied and,  accordingly,  the
                  aforementioned 60 day period shall commence as of such date of
                  actual knowledge.

         Notwithstanding anything to the contrary contained in the Securities of
         the Second Series,  this certificate or in the Indenture,  with respect
         to an event  described  in clause (b),  (c), (d) or (e) of this section
         (each such event, a "Guarantor Event"),  such Guarantor Event shall not
         be deemed to be an Event of Default  until 15 Business  Days after such
         Guarantor Event has occurred,  and, if, within such 15 day period,  the
         Company shall have provided to the Trustee a certificate or letter from
         Standard & Poor's  Corporation  (if the Securities of the Second Series
         are then rated by Standard & Poor's Corporation,  or, if the Securities
         of the Second  Series are then rated by another  nationally  recognized
         rating agency, then by such other agency) confirming that the rating on
         the  Securities  of the Second Series at such time is BBB or better (or
         the equivalent rating if by another rating agency), then such Guarantor
         Event shall be deemed to be waived by the Holders of the  Securities of
         the  Second  Series  and  shall  not  constitute  an Event  of  Default
         notwithstanding its continuation in fact;

12.      The Company covenants that the Securities of the Second Series shall
         rank  PARI  PASSU  with  all  existing  and  future   unsecured  Senior
         Indebtedness of the Company;

         For the  purposes  of this  covenant,  except  as  otherwise  expressly
         provided or unless the context otherwise requires:

         SENIOR  INDEBTEDNESS  means all  obligations  (other than  non-recourse
         obligations)  of, or guaranteed or assumed by, the Company for borrowed
         money,  including indebtedness for borrowed money or for the payment of
         money relating to any lease which is  capitalized  on the  consolidated
         balance sheet of the Company and its  subsidiaries  in accordance  with
         generally  accepted  accounting  principles  as in effect  from time to
         time,  or  evidenced  by  bonds,  debentures,  notes or  other  similar
         instruments,  and  in  each  case,  amendments,  renewals,  extensions,
         modifications  and refundings of any such  indebtedness or obligations,
         whether  existing  as of the  date of this  Indenture  or  subsequently
         incurred by the Company;

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13.      The obligations of the Company to make due and punctual payment of the
         principal of and premium, if any, and interest on the Securities of the
         Second  Series  shall be fully and  unconditionally  guaranteed  by the
         Guarantor,  as  provided  in  the  Guarantee  to be  delivered  by  the
         Guarantor to the Trustee. The form of such Guarantee is attached hereto
         as Exhibit B. The Trustee shall hold and enforce such Guarantee  solely
         for the benefit of the Holders of the  Securities of the Second Series.
         If any amounts shall become due and payable under such  Guarantee,  the
         Trustee,  in its own name and as trustee for such  Holders,  may demand
         payment,  may institute a judicial proceeding for the collection of the
         sums so due and unpaid,  may prosecute  such  proceeding to judgment or
         final  decree and may enforce the same and collect the moneys  adjudged
         or decreed to be payable in the manner provided by law;

14.      The  obligations  of the  Company  under the  Securities  of the Second
         Series and under the  Indenture  to the extent  related to such  series
         will be subject to  assumption  in whole by the  Guarantor  at any time
         (and upon such  assumption the Company shall be released and discharged
         from its  obligations  under the  Securities  of the Second  Series and
         under the  Indenture to the extent  related to such series) as provided
         in the form set forth in Exhibit A hereto.  Upon such  assumption,  the
         additional Events of Default contained in clauses (a), (c), (d) and (e)
         and the last  paragraph  of  Section  11 of this  certificate  shall be
         deleted and the following  modifications to the Indenture shall be made
         by  supplemental  indenture,  to  remain  in  effect  so  long  as  any
         Securities of the Second Series remain Outstanding:

         A.       The  provisions  contained in the Guarantee  under the heading
                  "Limitation  of  Liens"  shall be added to the  Indenture.  In
                  making such addition,  the word "Company" shall be substituted
                  for the  word  "Guarantor",  the  word  "Indenture"  shall  be
                  substituted   for  the  word   "Guarantee"   and  such   other
                  modifications as the context may require shall be made.

         B.       The additional Event of Default contained in clause (b) of
                  Section  11  of  this  certificate   shall  be  added  to  the
                  Indenture.  In making such addition,  the word "Company" shall
                  be substituted for the word "Guarantor".

15.      The Holders of the Securities of the Second Series, by their acceptance
         of  Securities  of the  Second  Series,  agree  that  the sale or other
         transfer  by the  Company  of the  Company's  wholly-owned  subsidiary,
         Automotive  Finance  Corporation,   does  not  constitute  the  Company
         "conveying  or otherwise  transferring  or leasing its  properties  and
         assets substantially as an entirety" within the meaning of Section 1101
         of the  Indenture.  Nothing  contained  in this  paragraph  15 shall be
         construed  in any way to imply that the sale or other  transfer  by the
         Company of the Company's  subsidiary,  Automotive Finance  Corporation,
         does  constitute the Company  "conveying or otherwise  transferring  or
         leasing its properties and assets  substantially as an entirety" within
         the meaning of Section 1101 of the Indenture;

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16.      If the Company shall make any deposit of money and/or Government
         Obligations with respect to any Securities of the Second Series, or any
         portion of the principal amount thereof, as contemplated by Section 701
         of the  Indenture  (a  "Deposit"),  the Company may also deliver to the
         Trustee  an  instrument  wherein  the  Company,   notwithstanding   the
         satisfaction  and  discharge  of its  indebtedness  in  respect of such
         Securities  of the Second  Series,  or such  portion  of the  principal
         amount thereof,  shall assume the obligation  (which shall be absolute,
         unconditional and guaranteed to the same extent as were the obligations
         of  the  Company  under  the   Securities  of  the  Second  Series)  to
         irrevocably  deposit with the Trustee or Paying  Agent such  additional
         sums of money, if any, or additional  Government  Obligations  (meeting
         the  requirements of Section 701), if any, or any combination  thereof,
         at such time or times,  as shall be necessary,  together with the money
         and/or Government Obligations theretofore so deposited, to pay when due
         the  principal of and  premium,  if any, and interest due and to become
         due on such Securities of the Second Series or portions thereof, all in
         accordance  with and subject to the  provisions  of said  Section  701;
         provided,  however,  that such instrument may state that the obligation
         of the  Company  to make  additional  deposits  as  aforesaid  shall be
         subject  to the  delivery  to the  Company  by the  Trustee of a notice
         asserting the  deficiency  accompanied  by an opinion of an independent
         public accountant of nationally  recognized  standing,  selected by the
         Trustee, showing the calculation thereof.

         If the Company  proposes to make any  Deposit,  the Company  shall also
                  deliver to the Trustee either:

         (A)      a tax indemnity agreement of the Company (a "Tax Indemnity
                  Agreement"),   reasonably  satisfactory  in  form,  scope  and
                  substance to the Trustee,  which Tax Indemnity Agreement shall
                  include,  inter  alia  (a) the  agreement  of the  Company  to
                  indemnify  any Holder of the  Securities  of the Second Series
                  ("Indemnitee") from any United States federal,  state or local
                  income  tax  liability   (including  penalties  and  interest)
                  resulting  from a Deposit as  contemplated  by Section 7.01 of
                  the Indenture (any such United States federal,  state or local
                  tax  liability   (including   penalties  and  interest)  being
                  referred to as a "Tax  Loss,")  together  with any  reasonable
                  costs and  expenses  incurred by such  Indemnitee  (including,
                  without  limitation,  reasonable  legal fees and  expenses) in
                  connection  with such Tax Loss; and (b)  provisions  such that
                  calculation  of any  Tax  Loss  is net  of  any  tax  benefits
                  associated with such Tax Loss in the current or any future tax
                  years (whether such tax benefit shall be by deduction, credit,
                  allocation,  step-up in basis or otherwise) or refunds to such
                  Indemnitee;  any calculations made pursuant to this (a) or (b)
                  to be made on a so-called "grossed-up" after-tax basis; or

         (B)      an Opinion of Thelen Reid & Priest  LLP,  or other  nationally
                  recognized  independent  counsel,  reasonably  satisfactory in
                  form, scope and substance to the Trustee,  that the Holders of
                  such  Securities  of the Second  Series,  or  portions  of the
                  principal amount thereof,  will not recognize income,  gain or
                  loss for United States federal income tax purposes as a result
                  of the Deposit,  the Deposit will not cause the Securities (or
                  any  deemed  exchanged  securities)  to  have  original  issue
                  discount as defined in the  Internal  Revenue Code or Treasury
                  Regulations,  and the  Securities  will be  subject  to United
                  States  federal  income tax on the same  amounts,  at the same
                  times and in the same  manner as if such  Deposit had not been
                  made.

17.      The  Securities  of the Second  Series  shall have such other terms and
         provisions as are provided in the form of the  Securities of the Second
         Series  set  forth  in  Exhibit  A  hereto,  and  shall  be  issued  in
         substantially such form;

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18.      The undersigned has read all of the covenants and conditions contained
         in  the  Indenture,  and  the  definitions  in the  Indenture  relating
         thereto,  relating  to the  issuance  of the  Securities  of the Second
         Series and in  respect of  compliance  with which this  certificate  is
         made;

19.      The  statements  contained  in this  certificate  are  based  upon  the
         familiarity  of the  undersigned  with  the  Indenture,  the  documents
         accompanying this certificate,  and upon discussions by the undersigned
         with  officers and  employees of the Company  familiar with the matters
         set forth herein;

20.      In the opinion of the undersigned, he has made such examination or
         investigation  as is necessary to enable the  undersigned to express an
         informed  opinion as to whether or not such  covenants  and  conditions
         have been complied with; and

21.      In the opinion of the  undersigned,  such  conditions and covenants and
         conditions precedent,  if any, provided for in the Indenture (including
         any covenants  compliance with which constitutes a condition precedent)
         relating to the  authentication  and delivery of the  Securities of the
         Second Series  requested in the accompanying  Company Order,  have been
         complied with.

                                       8

<PAGE>

         IN  WITNESS  WHEREOF,  the  undersigned  has  executed  this  Officer's
Certificate this 30th day of March, 2000.


                                                    /s/ William T. Stackhouse
                                                    ----------------------------
                                                    William T. Stackhouse
                                                    Chief Financial Officer


                                       9

<PAGE>
                                                                       EXHIBIT A
                            [non-registration legend]

THIS  SECURITY HAS NOT BEEN  REGISTERED  UNDER THE  SECURITIES  ACT OF 1933,  AS
AMENDED (THE "SECURITIES  ACT"). THE HOLDER HEREOF, BY PURCHASING THIS SECURITY,
AGREES THAT THIS SECURITY MAY NOT BE RESOLD, PLEDGED OR OTHERWISE TRANSFERRED AT
ANY TIME EXCEPT PURSUANT TO THE INDENTURE AND THE OFFICER'S CERTIFICATE CREATING
THIS SERIES AND PURSUANT TO REGISTRATION UNDER THE SECURITIES ACT AND APPLICABLE
STATE SECURITIES LAWS OR AN EXEMPTION THEREFROM.  THE HOLDER HEREOF SPECIFICALLY
ACKNOWLEDGES  AND AGREES  THAT THE COMPANY IS NOT  OBLIGATED  TO EFFECT ANY SUCH
REGISTRATION.

                           [FORM OF FACE OF SECURITY]

No.
   ----------------
[CUSIP No.           ]
           ----------
                                ADESA CORPORATION

                      8.10% SENIOR NOTE, SERIES B, DUE 2010

                  ADESA  Corporation,  a corporation duly organized and existing
under the laws of the State of Indiana  (herein  referred  to as the  "Company",
which  term  includes  any  successor  Person  under the  Indenture),  for value
received, hereby promises to pay to

-----------------------------------------------------------------------------,
or registered  assigns,  the principal  sum of  --------------------  Dollars on
March 30, 2010 (the "Stated Maturity" of the Securities of this series),  and to
pay interest on said principal sum, from and including,  March 30, 2000 or from,
and including,  the most recent Interest Payment Date to which interest has been
paid or duly  provided for,  semi-annually  on March 30 and September 30 of each
year,  commencing  September  30,  2000 at the rate of 8.10% per annum until the
principal hereof is paid or made available for payment;  PROVIDED that such rate
of interest  shall be 10.10% per annum with  respect to any days during which an
Event of Default with respect to the  Securities  of this series shall exist and
be continuing. The amount of interest payable on any Interest Payment Date shall
be computed on the basis of a 360-day year of twelve 30-day months.  Interest on
the Securities of this series will accrue from, and including, March 30, 2000 to
the  first  Interest  Payment  Date,  and  thereafter  will  accrue,  from,  and
including,  the last  Interest  Payment Date to which  interest has been paid or
duly provided for. 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 the  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 date fifteen (15) days
next preceding  such Interest  Payment Date (the Regular Record Date) or if such
date is not a Business Day, the next succeeding  Business Day. The Company shall
not be required to execute or to provide for the  registration of transfer of or
the  exchange of any  Security of the Second  Series  during a period of fifteen
(15) days next  preceding  any Interest  Payment Date for such Series.  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,

                                      A-1

<PAGE>

notice  whereof  shall be given to Holders of Securities of this series not less
than 10 days prior to such Special  Record Date,  all as more fully  provided in
the Indenture referred to on the reverse hereof.

                  Payment of the principal of and premium,  if any, and interest
on this  Security  will be made by wire  transfer to the extent  required by the
Note  Purchase  Agreements  dated  March 30,  2000,  between the Company and the
initial purchasers of the Securities of this series, 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; provided,  however, that to the extent that
payment  by wire  transfer  is not  required  by such Note  Purchase  Agreement,
payment of principal,  and premium,  if any, and each installment of interest on
this  Security  shall be made at the office or agency of the Company  maintained
for  that  purpose  in The  City  of New  York,  the  State  of  New  York  upon
presentation of this Security except that, at the option of the Company, payment
of interest on this  Security  may be made by check mailed to the address of the
person entitled thereto, as such address shall appear on the Security Register.

                  Reference  is hereby  made to the further  provisions  of this
Security set forth on the reverse hereof, which further provisions shall for all
purposes have the same effect as if set forth at this place.

                  Unless  the  certificate  of  authentication  hereon  has been
executed by the Trustee  referred to on the reverse hereof 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.

                                            ADESA Corporation

                                            By:
                                               ---------------------------------

ATTEST:

----------------------------


                     [FORM OF CERTIFICATE OF AUTHENTICATION]

                          CERTIFICATE OF AUTHENTICATION

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

Dated:

                                            THE BANK OF NEW YORK, as Trustee


                                            By:
                                               ---------------------------------
                                                     Authorized Signatory

                                      A-2

<PAGE>

                          [FORM OF REVERSE OF SECURITY]

                  This Security is one of a duly authorized  issue of securities
of the Company (herein called the "Securities"),  issued and to be issued in one
or more series under an Indenture,  dated as of May 15, 1996  (herein,  together
with any amendments thereto,  called the "Indenture",  which term shall have the
meaning assigned to it in such instrument),  between the Company and The Bank of
New York,  as Trustee  (herein  called the  "Trustee",  which term  includes any
successor  trustee  under the  Indenture),  and  reference is hereby made to the
Indenture,  including the Board Resolutions and Officer's Certificate filed with
the Trustee on March 30, 2000 creating the series designated on the face hereof,
for a statement of the  respective  rights,  limitations  of rights,  duties and
immunities  thereunder  of the  Company,  the  Trustee  and the  Holders  of the
Securities  and of the terms  upon  which  the  Securities  are,  and are to be,
authenticated  and delivered.  This Security is one of the series  designated on
the face hereof, limited in aggregate principal amount to $35,000,000.

         The  Securities of this series are subject to redemption  upon not less
than 30 days nor more  than 60  days'  notice  by  mail,  at the  option  of the
Company,  in whole, at any time, or in part, from time to time (but, if in part,
only in connection with redemptions of Securities of this series in an aggregate
principal  amount  of  $1,000  or any  integral  multiple  thereof),  at a price
("Redemption  Price")  equal  to the  sum of (A)  the  principal  amount  of the
Securities  of this series to be  redeemed,  plus (B) accrued  interest  thereon
(except if the  Redemption  Date shall be an Interest  Payment Date) to the date
selected for  redemption  ("Redemption  Date"),  plus (C) a premium equal to the
Make-Whole  Amount (as  hereinafter  defined).  Each Security of this series (or
portion thereof) so redeemed shall be canceled (or such portion thereof shall be
deemed to have been canceled) and, thereafter, shall not be reissued.

         Notice of a make-whole  redemption shall be accompanied by an Officer's
Certificate  certifying:  (A) the preliminary redemption price (the "Preliminary
Redemption Price"),  including the aggregate applicable principal,  interest and
Make-Whole  Amount,  and (B) the portion of such  Preliminary  Redemption  Price
allocable to each Security of this series.  On or prior to the Redemption  Date,
the Company shall deliver to each Holder of the Securities of this series and to
the Trustee a further Officer's Certificate certifying (X) the Redemption Price,
including the aggregate  applicable  principal,  interest and Make-Whole Amount,
and (Y) the portion of such Redemption  Price allocable to each Security of this
series.

         Any Holder of the  Securities  of this  series  shall have the right to
contest  the  calculation  of any  Redemption  Price  to be paid or paid to such
Holder as the result of any make-whole  redemption by delivering  written notice
to the Company,  within five (5) Business  Days of receipt by such Holder of the
further Officer's  Certificate referred to in the preceding  paragraph,  setting
forth such Holder's  objection.  Within five (5) Business Days of receipt by the
Company  of any such  notice,  the  Company  shall  notify  each  Holder of such
Securities of this series and the Trustee of the nature of such objection and of
the Company's  response thereto.  Any increase in a Redemption Price made by the
Company  as a result  of any such  objection  shall be paid to each  Holder  and
acceptance  thereof  shall not be  deemed  to be a waiver by such  Holder of any
right to  contest  the amount of such  payment;  provided,  that  notice of such
contest has been  delivered to the Company  within five (5) Business  Days after
receipt of such further Officer's Certificate.

         The Trustee  shall be under no duty to inquire into,  may  conclusively
presume  the  correctness  of, and shall be fully  protected  in acting upon the
Company's calculation of any Preliminary  Redemption Price, any Redemption Price
and any increase therein.

                                      A-3

<PAGE>

         The term "BUSINESS DAY" means any day other than a Saturday or a Sunday
or a day on which banking institutions in The City of New York are authorized or
required  by law or  executive  order to  remain  closed  or a day on which  the
Corporate Trust Office of the Trustee is closed for business.

         The term "DISCOUNT RATE" means the Treasury Rate plus .50%.

         The term  "MAKE-WHOLE  AMOUNT" means an amount equal to the excess,  if
any, of (A) the sum of the present values, on the day after the Redemption Date,
of the amount of each  remaining  scheduled  payment of interest  (exclusive  of
interest  accrued to the Redemption  Date) on and principal of the Securities of
this series,  or portion of such payment,  which will not be required to be made
as a result of such optional redemption (each such amount discounted  separately
at the Discount  Rate,  to be  determined  (1) with  respect to the  Preliminary
Redemption  Price,  as of the third  Business  Day before the date of mailing of
notice of an optional redemption,  and (2) with respect to the Redemption Price,
as  of  the  third   Business  Day  before  the  Redemption   Date,   compounded
semi-annually,  from the date such  amount  would have been  due),  over (B) the
principal amount of such Securities of this series to be optionally redeemed.

         The  term  "TREASURY  RATE"  means  the  rate  per  annum  equal to the
arithmetic  average of (A) the average yields on issues of  non-callable  United
States Treasury  securities adjusted to a constant maturity equal to the Life to
Maturity  of the  Securities  of  this  series  (determined,  if  necessary,  by
interpolating  such yields on  non-callable  United States  Treasury  securities
adjusted to the particular constant maturities greater than (but nearest to) and
less  than (but  nearest  to) the Life to  Maturity  of the  Securities  of this
series),  as  published  by the Federal  Reserve  Board for release on the first
Business Day  preceding  the Business Day on which such  determination  shall be
made in its Statistical  Release H.15(519) under the heading "Treasury  Constant
Maturities," for the two calendar weeks ending on the two Wednesdays immediately
preceding the date of such release, or (B) if such average yields shall not have
been published for such periods,  two such reasonably  comparable indices as may
be designated  for such period by the Company and not objected to by the Holders
of a majority in aggregate  unpaid  principal  amount of the  Securities of this
series then Outstanding.

         The term "LIFE TO MATURITY" of the Securities of this series means,  as
of the date of the determination thereof, the number of years (calculated to the
nearest one-twelfth) which will elapse between the date of determination and the
Stated Maturity of the Securities of this series.

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

                  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.

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

                  The  Indenture  permits,  with certain  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 aggregate 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 aggregate  principal  amount of the Securities of each series at
the time Outstanding, on behalf of the Holders of all Securities of such series,
to waive compliance by the

                                      A-4
<PAGE>

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 such Holder shall have previously given
the Trustee written notice of a continuing  Event of Default with respect to the
Securities of this series,  the Holders of not less than a majority in aggregate
principal  amount of the  Securities of such series at the time  Outstanding  in
respect of which an Event of Default shall have occurred and be continuing 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,
and the  Trustee  shall not have  received  from the  Holders of a  majority  in
aggregate  principal  amount of Securities of all series at the time Outstanding
in respect of which an Event of Default  shall have occurred and be continuing a
direction inconsistent with such request, and 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  in  denominations  of $1,000 and any  integral  multiple
thereof. As provided in the Indenture and subject to certain limitations therein
set forth,  Securities  of this  series are  exchangeable  for a like  aggregate
principal  amount  of  Securities  of  this  series  and of  like  tenor  and of
authorized denominations, as requested by the Holder surrendering the same.

                  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,  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, 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 Securities of this series are entitled to the benefit of a
Guarantee of Minnesota  Power,  Inc.  (together with its successors and assigns,
the "Guarantor") dated as of March 30, 2000 delivered to the Trustee as provided
therein;  provided,  however,  that such  Guarantee  shall be  terminated if the
obligations of the Company under the Securities of this series and the Indenture
to the  extent  related  to such  series  are  assumed  by  Guarantor  as herein
provided.

                  Unless an Event of Default, or an event which, after notice or
lapse of time or both, would become an Event of Default, shall have occurred and
be  continuing,  the  obligations  of the Company  under the  Securities of this
series and the Indenture to the extent  related to such series may be assumed in
whole, on a full recourse basis, by the Guarantor at any time (and upon any such
assumption

                                      A-5
<PAGE>

the Company  shall be released and  discharged  from its  obligations  under the
Securities  of this  series  and the  Indenture  to the  extent  related to such
series);  PROVIDED,  HOWEVER,  that such  assumption  shall be  subject  to, and
permitted only upon the fulfillment and satisfaction of, the following terms and
conditions:  (a) an  assumption  agreement and a  supplemental  indenture to the
Indenture  evidencing such assumption  shall be in substance and form reasonably
satisfactory to the Trustee and shall,  INTER ALIA,  include  modifications  and
amendments to the Indenture making the obligations  under the Securities of this
series and under the  Indenture  to the extent  related to such  series  primary
obligations of the Guarantor,  substituting the Guarantor for the Company in the
form of the  Securities of this series and in provisions of the Indenture to the
extent related to such series,  modifying the Indenture to add the limitation of
lien  provision  contained in the Guarantee  and  substitute  the  cross-default
provision applicable to the Guarantor, and releasing and discharging the Company
from its  obligations  under the  Securities of this series and the Indenture to
the extent  related to such series;  and (b) the Trustee shall have received (i)
an executed counterpart of such assumption agreement and supplemental indenture;
(ii)  evidence  satisfactory  to the Trustee and the Company that all  necessary
authorizations,  consents, orders, approvals,  waivers, filings and declarations
of or with, Federal,  state, county,  municipal,  regional or other governmental
authorities, agencies or boards (collectively,  "Governmental Actions") relating
to such  assumption  have been duly  obtained  and are in full force and effect,
(iii) evidence  satisfactory to the Trustee that any security  interest intended
to be created by the Indenture is not in any material way adversely  affected or
impaired by any of the agreements or  transactions  relating to such  assumption
and (iv) an Opinion of Counsel for the  Guarantor,  reasonably  satisfactory  in
substance, scope and form to the Trustee and the Company, to the effect that (A)
the supplemental  indenture evidencing such assumption has been duly authorized,
executed and delivered by the  Guarantor,  (B) the execution and delivery by the
Guarantor  of  such   supplemental   indenture  and  the   consummation  of  the
transactions  contemplated thereby do not contravene any provision of law or any
governmental   rule  applicable  to  the  Guarantor  or  any  provision  of  the
Guarantor's charter documents or by-laws and do not contravene any provision of,
or  constitute a default  under,  or result in the creation or imposition of any
lien  upon any of the  Guarantor's  properties  or assets  under any  indenture,
mortgage,  contract or other  agreement to which the  Guarantor is a party or by
which the Guarantor or any of its properties  may be bound or affected,  (C) all
necessary  Governmental  Actions  relating  to such  assumption  have  been duly
obtained  and  are  in  full  force  and  effect  and  (D)  such  agreement  and
supplemental  indenture  constitute the legal, valid and binding  obligations of
the Guarantor,  enforceable in accordance with their respective terms, except as
such  enforceability  may  be  limited  by  applicable  bankruptcy,  insolvency,
reorganization, moratorium or other similar laws at the time in effect affecting
the rights of creditors generally.

                  All  terms  used in this  Security  which are  defined  in the
Indenture shall have the meanings assigned to them in the Indenture.

                                      A-6

<PAGE>

                                                                       EXHIBIT B

                               [FORM OF GUARANTEE]
                                    GUARANTEE
                                       OF
                              MINNESOTA POWER, INC.

                  For value received,  Minnesota Power, Inc., a corporation duly
organized and existing  under the laws of the State of Minnesota  (herein called
the  "Guarantor"),  hereby fully and  unconditionally  guarantees to the Trustee
under the Indenture,  dated as of May 15, 1996,  between ADESA  Corporation (the
"Company")  and The Bank of New York, as Trustee  (together  with any amendments
thereto,  the  "Indenture,"  which term shall have the meaning assigned to it in
such  instrument),  the  payment of the  obligations  of the  Company  under the
Securities  of the Second  Series and the  Indenture  relating  to such  series,
including, without limitation, (i) the due and punctual payment of the principal
of and premium, if any, and interest on the Securities of the Second Series when
and as the same  shall  become due and  payable,  whether  at  maturity  or upon
redemption or upon declaration or otherwise,  according to the terms thereof and
of the Indenture, and (ii) the due and punctual payment of any amounts which may
be payable by the  Company  under or  pursuant  to the Tax  Indemnity  Agreement
referred  to  in  paragraph  16 of  the  Officer's  Certificate  of  William  T.
Stackhouse,  Chief  Financial  Officer of the Company  dated March 30, 2000 (the
"Tax Indemnity  Payments").  In case of the failure of the Company punctually to
pay any such principal,  premium,  if any, or interest or Tax Indemnity Payment,
the Guarantor hereby agrees to cause any such payment to be made punctually when
and as the same  shall  become due and  payable,  whether  at  maturity  or upon
redemption or upon declaration or otherwise, and as if such payment were made by
the Company. The Guarantor hereby agrees that its obligations hereunder shall be
full and unconditional, irrespective of the validity, legality or enforceability
of the  Securities  of the Second  Series or the  Indenture,  the absence of any
action  to  enforce  the  same,  the  waiver  or  consent  by the  Holder of the
Securities of the Second Series or by the Trustee with respect to any provisions
thereof or of said Indenture,  the recovery of any judgment  against the Company
or any  action  to  enforce  the  same or any  other  circumstance  which  might
otherwise  constitute a legal or equitable  discharge or defense of a guarantor.
The Guarantor hereby waives diligence, presentment, demand of payment, filing of
claims with a court in the event of merger or  bankruptcy  of the  Company,  any
right to require a proceeding first against the Company,  protest or notice with
respect to the  Securities  of the Second Series or the  indebtedness  evidenced
thereby, and all demands whatsoever,  and covenants that this Guarantee will not
be discharged except by complete performance of the obligations contained in the
Securities of the Second Series and in this Guarantee.

                  The Guarantor  hereby  guarantees  that the obligations of the
Company  under the  Securities  of the Second  Series and the  Indenture  to the
extent  related to such series will be paid to the  Trustee  without  set-off or
counterclaim or other reduction  whatsoever  (whether for taxes,  withholding or
otherwise) in lawful currency of the United States of America.

                  The obligations of the Guarantor  hereunder are independent of
the obligations of the Company under the Securities of the Second Series and the
Indenture to the extent related to such series, and a separate action or actions
may be brought and prosecuted  against the Guarantor whether or not an action or
proceeding  is brought  against  the  Company  and whether or not the Company is
joined  in any  such  action  or  proceeding.  The  liability  of the  Guarantor
hereunder  is full and  unconditional  and (to the extent  permitted by law) the
liability  and  obligations  of the Guarantor  hereunder  shall not be released,
discharged,  mitigated,  waived, impaired or affected in whole or in part by any
circumstance  (including any statute of  limitations)  (other than payment) that
might  constitute  a defense  available  to, or  discharge of the Company or the
Guarantor,   including,   without   limitation,   any  termination,   amendment,

                                      B-1

<PAGE>

modification, addition, deletion, supplement or other change to any of the terms
of the Securities of the Second Series or the Indenture, any failure on the part
of the Trustee or any Holder to enforce,  assert or exercise any right, power or
remedy,  any  waiver,  consent,  extension,  renewal,  indulgence,   compromise,
release,  settlement,  refunding or other action or inaction under or in respect
of any obligation or liability of the Company or the Guarantor or the Trustee or
any  Holder,  or any  modification,  compromise,  settlement  or  release by the
Trustee,  or by  operation  of  law or  otherwise,  of  the  obligations  or the
liability of the Company under the Securities of the Second Series,  in whole or
in part.

                  The  Guarantor  agrees  that if at any time all or any part of
any payment at any time received by the Trustee or the Holders of the Securities
of the Second  Series is or must be rescinded or returned by the Trustee or such
Holders  for  any  reason  whatsoever   (including,   without  limitation,   the
insolvency,  reorganization or bankruptcy of the Company),  then the Guarantor's
obligations hereunder shall, to the extent of the payment rescinded or returned,
be deemed to have continued in existence  notwithstanding  such previous receipt
by the Trustee or such Holders, and the Guarantor's  obligations hereunder shall
continue to be effective or  reinstated,  as the case may be, as if such payment
had never been made.

                  The  failure of the  Trustee  to  enforce  any right or remedy
hereunder,  or promptly to enforce any right or remedy hereunder, or promptly to
enforce any such right or remedy,  shall not  constitute a waiver  thereof,  nor
give rise to any estoppel against the Trustee, nor excuse the Guarantor from its
obligations hereunder.

                  No reference  herein to the Indenture and no provision of this
Guarantee  or of the  Indenture  shall  alter or  impair  the  guarantee  of the
Guarantor, which is absolute and unconditional,  of the due and punctual payment
of the  principal  of and  premium,  if any, and interest on the Security of the
series upon which this Guarantee is endorsed and of any Tax Indemnity Payments.

                  The Guarantor  shall be subrogated to all rights of the Holder
of the  Securities  of the Second  Series  against the Company in respect of any
amounts paid by the Guarantor  pursuant to the provisions of this Guarantee upon
payment by the Guarantor of all amounts due and payable under such Guarantee.

                  This  Guarantee  shall be  irrevocable  unless  terminated  as
provided  herein.  This Guarantee shall be terminated upon the assumption by the
Guarantor of the  obligations  of the Company under the Securities of the Second
Series and the Indenture to the extent related to such series as provided in the
terms of such Securities.

                  All  capitalized  terms used in this  Guarantee  which are not
defined  herein but are defined in the  Indenture  shall have the  meanings  set
forth in the Indenture.

                  This Guarantee shall be deemed to be a contract made under the
laws of the State of New York and  shall for all  purposes  be  governed  by and
construed in accordance with the laws of such State.

SECTION 1.  CONSOLIDATION, MERGER AND SALE OF ASSETS.

                  During the term of this  Guarantee,  the  Guarantor  shall not
consolidate  with or merge into any other  corporation,  or convey or  otherwise
transfer or lease its properties and assets  substantially as an entirety to any
Person, unless

               (a) the corporation  formed by such  consolidation  or into which
      the  Guarantor is merged or the Person  which  acquires by  conveyance  or
      transfer,  or which  leases,  the  properties  and assets of the

                                      B-2
<PAGE>

      Guarantor  substantially  as an entirety  shall be a Person  organized and
      validly existing under the laws of the United States, any State thereof or
      the District of Columbia,  and shall expressly assume,  the obligations of
      the Guarantor under this Guarantee;

               (b) immediately  after giving effect to such transaction no Event
      of Default,  and no event  which,  after  notice or lapse of time or both,
      would become an Event of Default,  shall have occurred and be  continuing;
      and

               (c)  the  Guarantor  shall  have  delivered  to  the  Trustee  an
      Officer's  Certificate (as hereinafter  defined) and an Opinion of Counsel
      (as hereinafter  defined),  each stating that such consolidation,  merger,
      conveyance,  or other  transfer or lease and such  supplemental  indenture
      comply  with  this  Guarantee  and that all  conditions  precedent  herein
      provided for relating to such transactions have been complied with.

               Upon any  consolidation  by the  Guarantor  with or merger by the
Guarantor  into any other  corporation or any  conveyance,  or other transfer or
lease of the properties and assets of the Guarantor substantially as an entirety
in  accordance  with this  Section,  the  successor  corporation  formed by such
consolidation  or into which the Guarantor is merged or the Person to which such
conveyance,  transfer or lease is made shall succeed to, and be substituted for,
and may exercise  every right and power of, the Guarantor  under this  Guarantee
and under the terms of the Securities of the Second Series (including assumption
of the  obligations  under the  Securities  of the  Second  Series and under the
Indenture to the extent  related to such series) with the same effect as if such
successor Person had been named as the Guarantor herein, and thereafter,  except
in the  case of a  lease,  the  predecessor  Person  shall  be  relieved  of all
obligations and covenants under this Guarantee.

SECTION 1A.       FINANCIAL INFORMATION.

         During the term of this  Guarantee,  the Guarantor shall deliver to the
Holders of the Securities of the Second Series:

         (a)  Quarterly  Statements - promptly,  and in any event within 60 days
after  the end of each  quarterly  fiscal  period  in  each  fiscal  year of the
Guarantor  (other  than the last  quarterly  fiscal  period of each such  fiscal
year), duplicate copies of:

                  (i)   consolidated balance sheets of the Guarantor as at the
         end of such quarter, and

                  (ii)  consolidated  statements  of  income,  cash  flows,  and
         changes in shareholders'  equity, of the Guarantor for such quarter and
         (in the case of the second and third  quarters)  for the portion of the
         fiscal  year ending with such  quarter,  setting  forth in each case in
         comparative  form the  figures  for the  corresponding  periods  in the
         previous fiscal year, all in reasonable detail,  prepared in accordance
         with GAAP applicable to quarterly financial statements  generally,  and
         certified  by an  Authorized  Officer  as  fairly  presenting,  in  all
         material  respects,  the  financial  position  of the  companies  being
         reported on and their results of operations and cash flows,  subject to
         changes resulting from year-end adjustments,

provided,  that delivery within the time period specified above of copies of the
Guarantor's  Quarterly  Report on Form 10-Q which is prepared in compliance with
the  requirements  therefor and which is filed with the  Securities and Exchange
Commission shall be deemed to satisfy the requirements of this Section 1A(a);

                                      B-3

<PAGE>

         (b) Annual  Statements  -  promptly,  and in any event  within 105 days
after the end of each fiscal year of the Guarantor, duplicate copies of,

                  (i)   consolidated balance sheets of the Guarantor, as at the
         end of such year, and

                  (ii)  consolidated  statements  of  income,  cash  flows,  and
         changes  in  shareholders'  equity,  of the  Guarantor,  for such year,
         setting  forth in each case in  comparative  form the  figures  for the
         previous fiscal year, all in reasonable detail,  prepared in accordance
         with GAAP, certified by an Authorized Officer as fairly presenting,  in
         all material  respects,  the financial  position of the companies being
         reported  on and  their  results  of  operations  and  cash  flows  and
         accompanied  by an opinion  thereon  of  independent  certified  public
         accountants of recognized national standing,  which opinion shall state
         that  such  financial   statements  present  fairly,  in  all  material
         respects,  the financial  position of the companies being reported upon
         and their results of  operations  and cash flows and have been prepared
         in conformity with GAAP, and that the  examination of such  accountants
         in  connection  with  such  financial   statements  has  been  made  in
         accordance with generally  accepted auditing  standards,  and that such
         audit   provides   a   reasonable   basis  for  such   opinion  in  the
         circumstances,

provided  that the  delivery  within  the  time  period  specified  above of the
Guarantor's  Annual Report on Form 10-K for such fiscal year  (together with the
Guarantor's  annual report to  shareholders  if any,  prepared  pursuant to Rule
14a-3  under  the  Exchange  Act)  which are  prepared  in  accordance  with the
requirements  therefor  and which are filed  with the  Securities  and  Exchange
Commission, shall be deemed to satisfy the requirements of this Section 1A(b);

SECTION 2. LIMITATION ON LIENS.

               A. The Guarantor  shall not suffer any Lien (other than Permitted
Liens)  to be  created  or to  exist  upon any  property  (other  than  Excepted
Property) of the Guarantor,  real, personal or mixed, of whatever kind or nature
and  located  in the  State  of  Minnesota,  whether  owned  at the  date of the
execution and delivery of this  Guarantee or hereafter  acquired,  all except as
expressly contemplated in subsection B of this Section.

               B. The provisions of subsection A shall not prohibit the creation
or existence of any Lien on property of the Guarantor which secures indebtedness
for borrowed money if either:

                       1. the Guarantor shall make effective provision whereby
               this  Guarantee  shall be secured  equally and  ratably  with the
               indebtedness secured by such Lien; or

                       2. the  Guarantor  shall  deliver to the  Trustee  bonds,
               notes or other  evidences  of  indebtedness  secured by such Lien
               (hereinafter  called "Secured  Obligations")  (a) in an aggregate
               principal  amount equal to the aggregate  principal amount of the
               Securities  of the Second Series then  Outstanding,  (b) maturing
               (or being subject to mandatory  redemption) on March 30, 2010 and
               (c)   containing,   in  addition  to  any  mandatory   redemption
               provisions  applicable  to all  Secured  Obligations  outstanding
               under such Lien and any mandatory redemption provisions contained
               therein  pursuant  to  clause  (b)  above,  mandatory  redemption
               provisions  correlative  to  the  provisions,  if  any,  for  the
               mandatory redemption (pursuant to a sinking fund or otherwise) of
               the Securities of the Second Series or for the redemption thereof
               at the option of the Holder, as well as a provision for mandatory
               redemption   upon  an

                                      B-4

<PAGE>

               acceleration of the maturity of all Outstanding Securities of the
               Second  Series  following  an Event of  Default  (such  mandatory
               redemption   to  be  rescinded   upon  the   rescission  of  such
               acceleration);  it being  expressly  understood that such Secured
               Obligations  (x) may, but need not, bear  interest,  (y) may, but
               need not,  contain  provisions for the redemption  thereof at the
               option  of the  issuer,  any  such  redemption  to be  made  at a
               redemption  price or prices  not less than the  principal  amount
               thereof  and (z) shall be held by the  Trustee for the benefit of
               the Holders of all  Securities  of the Second Series from time to
               time Outstanding subject to such terms and conditions relating to
               surrender  to  the  Guarantor,  transfer  restrictions,   voting,
               application  of  payments of  principal  and  interest  and other
               matters as shall be set forth in an indenture supplemental hereto
               specifically  providing  for the  delivery to the Trustee of such
               Secured Obligations.

               C. If the Guarantor shall elect either of the alternatives
 described in subsection B, the Guarantor shall deliver to the Trustee:

                       1. an  amendment  to this  Guarantee  (a)  together  with
               appropriate inter-creditor  arrangements,  whereby this Guarantee
               shall be secured by the Lien  referred to in subsection B equally
               and ratably with all other  indebtedness  secured by such Lien or
               (b)  providing  for  the  delivery  to  the  Trustee  of  Secured
               Obligations;

                       2. an  Officer's  Certificate  (a) stating  that,  to the
               knowledge of the signer, (I) no Event of Default has occurred and
               is  continuing  and (II) no event has occurred and is  continuing
               which  entitles the secured  party under such Lien to  accelerate
               the maturity of the indebtedness  outstanding  thereunder and (b)
               stating the aggregate principal amount of indebtedness  issuable,
               and then proposed to be issued, under and secured by such Lien;

                       3. an Opinion of Counsel (a) if this  Guarantee  is to be
               secured by such Lien,  to the effect that all  Securities  of the
               Second  Series then  Outstanding  are  entitled to the benefit of
               such  Lien  equally  and  ratably  with  all  other  indebtedness
               outstanding under such Lien or (b) if Secured  Obligations are to
               be  delivered  to the  Trustee,  to the effect that such  Secured
               Obligations  have been duly issued under such Lien and constitute
               valid  obligations,  entitled to the benefit of such Lien equally
               and ratably with all other  indebtedness  then outstanding  under
               such Lien.

               D. For all purposes of this Guarantee, except as otherwise
 expressly provided or unless the context otherwise requires:

                       "EXCEPTED PROPERTY" means

                       (a)  all  cash on hand or in  banks  or  other  financial
               institutions,  deposit  accounts,  shares of stock,  interests in
               general or  limited  partnerships,  bonds,  notes,  evidences  of
               indebtedness and other securities not hereafter paid or delivered
               to,  deposited with or held by the Trustee  hereunder or required
               so to be;

                       (b) all  contracts,  leases,  operating  agreements,  and
               other  agreements  of  whatsoever  kind and nature;  all contract
               rights,  bills,  notes and other  instruments  and chattel  paper
               (except to the extent that any of the same constitute securities,
               in which case they are  separately  excepted from this  Guarantee
               under clause (a) above); all revenues,  income and earnings,  all
               accounts,  accounts  receivable  and unbilled  revenues,  and all
               rents,  tolls,  issues,  product and  profits,  claims,  credits,
               demands  and  judgments;  all  governmental  and other  licenses,
               permits, franchises, consents and allowances; all patents, patent
               licenses  and other

                                      B-5

<PAGE>

               patent  rights,  patent  applications,  trade names,  trademarks,
               copyrights,   claims,   credits,   choses  in  action  and  other
               intangible  property and general intangibles  including,  but not
               limited to, computer software;

                       (c)  all  automobiles,   buses,   trucks,  truck  cranes,
               tractors,  trailers and similar  vehicles and movable  equipment;
               all rolling stock,  rail cars and other railroad  equipment;  all
               vessels, boats, barges and other marine equipment; all airplanes,
               helicopters,  aircraft  engines and other flight  equipment;  all
               parts,  accessories  and supplies used in connection  with any of
               the foregoing;  and all personal  property of such character that
               the  perfection  of a  security  interest  therein  or other Lien
               thereon is not  governed  by the  Uniform  Commercial  Code as in
               effect in the jurisdiction in which such property is located;

                       (d) all goods,  stock in trade,  wares,  merchandise  and
               inventory  held for the purpose of sale or lease in the  ordinary
               course of business; all materials,  supplies, inventory and other
               items of personal  property which are consumable  (otherwise than
               by ordinary  wear and tear) in their use in the  operation of any
               property of the  Guarantor;  all fuel,  including  nuclear  fuel,
               whether  or not  any  such  fuel is in a form  consumable  in the
               operation of any property of the  Guarantor,  including  separate
               components  of any fuel in the  forms in  which  such  components
               exist at any time  before,  during or after the period of the use
               thereof as fuel; all hand and other portable tools and equipment;
               all furniture and furnishings; and computers and data processing,
               data storage,  data  transmission,  telecommunications  and other
               facilities, equipment and apparatus, which, in any case, are used
               primarily  for   administrative   or  clerical  purposes  or  are
               otherwise not necessary for the operation or  maintenance  of the
               facilities, machinery, equipment or fixtures of the Guarantor for
               (i) the  generation,  transmission  or  distribution  of electric
               energy, (ii) the transmission,  storage or distribution of gas or
               (iii) the appropriation, storage, transmission or distribution of
               water;

                       (e) all coal,  ore,  gas, oil and other  minerals and all
               timber,  and all rights and  interests  in any of the  foregoing,
               whether or not such  minerals or timber  shall have been mined or
               extracted or otherwise  separated from the land; and all electric
               energy,  gas  (natural  or  artificial),  steam,  water and other
               products   generated,   produced,   manufactured,   purchased  or
               otherwise acquired by the Guarantor;

                       (f) all real  property,  leaseholds,  gas rights,  wells,
               gathering,  tap or other pipe lines, or facilities,  equipment or
               apparatus,  in any  case  used  or to be used  primarily  for the
               production or gathering of natural gas;

                       (g) all hydroelectric  plants and all lands, power sites,
               flowage rights, water rights, riparian rights, permits, licenses,
               franchises,   privileges,   leaseholds,  water  locations,  water
               appropriations,  ditches,  flumes,  reservoirs,  reservoir sites,
               canals,  raceways,   dams,  dam  sites,  aqueducts,   structures,
               facilities,  equipment,  or apparatus,  in any case used or to be
               used  primarily in connection  with the  Company's  hydroelectric
               plants; and

                       (h) all leasehold interests held by the Guarantor a
               lessee.


                       "LIEN" means any mortgage, deed of trust, pledge,
security  interest,  encumbrance,  easement,  lease,  reservation,  restriction,
servitude,  charge or similar  right and any other lien of any kind,  including,
without limitation, any conditional sale or other title retention agreement, any
lease  in the  nature  thereof,  and  any  defect,  irregularity,  exception  or
limitation in record title.

                                      B-6

<PAGE>

                       "OFFICER'S  CERTIFICATE" means a certificate signed by an
Authorized Officer and delivered to the Trustee.  "Authorized Officer" means the
Chairman of the Board,  the President,  any Vice President,  the Treasurer,  any
Assistant  Treasurer,  or any  other  officer  or  agent of the  Guarantor  duly
authorized  by the Board of Directors  to act in respect of matters  relating to
this Guarantee.  "Board of Directors" means either the board of directors of the
Guarantor or any committee  thereof duly authorized to act in respect of matters
relating to this Guarantee.

                       "OPINION OF COUNSEL" means a written opinion of counsel,
who may be  counsel  for the  Guarantor,  or  other  counsel  acceptable  to the
Trustee.

                       "PERMITTED  LIENS" means, as of any particular  time, any
of the following:

                       (a) Liens for taxes,  assessments and other  governmental
               charges or  requirements  which are not  delinquent  or which are
               being contested in good faith by appropriate proceedings;

                       (b) mechanics',  workmen's,  repairmen's,  materialmen's,
               warehousemen's  and  carriers'  Liens,  other  Liens  incident to
               construction,  Liens  or  privileges  of  any  employees  of  the
               Guarantor  for salary or wages earned,  but not yet payable,  and
               other  Liens,  including  without  limitation  Liens for worker's
               compensation  awards,  arising in the ordinary course of business
               for charges or requirements which are not delinquent or which are
               being contested in good faith and by appropriate proceedings;

                       (c) Liens in respect of attachments,  judgments or awards
               arising out of judicial or  administrative  proceedings (i) in an
               aggregate amount not exceeding Ten Million Dollars  ($10,000,000)
               or (ii) with  respect  to which the  Guarantor  shall (X) in good
               faith be prosecuting an appeal or other proceeding for review and
               with respect to which the Guarantor  shall have secured a stay of
               execution pending such appeal or other proceeding or (Y) have the
               right to prosecute an appeal or other proceeding for review;

                       (d) easements,  leases,  reservations  or other rights of
               others in, on, over,  and/or across,  and laws,  regulations  and
               restrictions affecting, and defects,  irregularities,  exceptions
               and limitations in title to, the property of the Guarantor or any
               part thereof;  provided,  however,  that such easements,  leases,
               reservations, rights, laws, regulations,  restrictions,  defects,
               irregularities,   exceptions  and   limitations  do  not  in  the
               aggregate  materially  impair  the  use by the  Guarantor  of its
               property  considered  as a whole for the purposes for which it is
               held by the Guarantor;

                       (e) defects,  irregularities,  exceptions and limitations
               in title to real property  subject to  rights-of-way  in favor of
               the Guarantor or otherwise or used or to be used by the Guarantor
               primarily for  right-of-way  purposes or real property held under
               lease,  easement,  license or similar right;  provided,  however,
               that (i) the  Guarantor  shall have  obtained  from the  apparent
               owner or owners of such real property a sufficient  right, by the
               terms  of  the  instrument  granting  such  right-of-way,  lease,
               easement,  license or similar  right,  to the use thereof for the
               purposes  for which the  Guarantor  acquired  the same,  (ii) the
               Guarantor has power under eminent  domain or similar  statutes to
               remove such defects, irregularities, exceptions or limitations or
               (iii) such defects,  irregularities,  exceptions and  limitations
               may be otherwise  remedied  without undue effort or expense;  and
               defects,  irregularities,  exceptions and limitations in title to
               flood lands, flooding rights and/or water rights;

                                      B-7
<PAGE>

                       (f)  Liens  securing  indebtedness  or other  obligations
               neither  created,  assumed nor guaranteed by the Guarantor nor on
               account of which it customarily  pays interest upon real property
               or  rights  in or  relating  to  real  property  acquired  by the
               Guarantor for the purpose of the  transmission or distribution of
               electric  energy,  gas or water,  for the purpose of  telephonic,
               telegraphic, radio, wireless or other electronic communication or
               otherwise for the purpose of obtaining rights-of-way;

                       (g)  leases  existing  at the date of the  execution  and
               delivery  of this  Guarantee  affecting  properties  owned by the
               Guarantor at said date and renewals and extensions  thereof;  and
               leases affecting such properties  entered into after such date or
               affecting  properties  acquired by the Guarantor  after such date
               which, in either case, (i) have respective terms of not more than
               ten (10) years (including extensions or renewals at the option of
               the  tenant)  or (ii)  do not  materially  impair  the use by the
               Guarantor  of such  properties  for the  respective  purposes for
               which they are held by the Guarantor;

                       (h) Liens vested in lessors,  licensors,  franchisors  or
               permitters  for rent or other  amounts to become due or for other
               obligations or acts to be performed, the payment of which rent or
               the  performance  of which other  obligations or acts is required
               under leases, subleases, licenses, franchises or permits, so long
               as the payment of such rent or other  amounts or the  performance
               of such other  obligations  or acts is not delinquent or is being
               contested in good faith and by appropriate proceedings;

                       (i) controls,  restrictions,  obligations,  duties and/or
               other burdens imposed by federal,  state, municipal or other law,
               or by rules,  regulations or orders of Governmental  Authorities,
               upon  any  property  of the  Guarantor  or the  operation  or use
               thereof or upon the Guarantor with respect to any of its property
               or the operation or use thereof or with respect to any franchise,
               grant,  license,  permit or public  purpose  requirement,  or any
               rights   reserved  to  or   otherwise   vested  in   Governmental
               Authorities   to   impose   any  such   controls,   restrictions,
               obligations, duties and/or other burdens;

                       (j) rights  which  Governmental  Authorities  may have by
               virtue of franchises,  grants, licenses, permits or contracts, or
               by virtue of law, to purchase, recapture or designate a purchaser
               of or order  the sale  of,  any  property  of the  Guarantor,  to
               terminate franchises,  grants,  licenses,  permits,  contracts or
               other  rights or to regulate  the  property  and  business of the
               Guarantor;   and  any  and  all   obligations  of  the  Guarantor
               correlative to any such rights;

                       (k) Liens required by law or governmental regulations (i)
               as a condition to the transaction of any business or the exercise
               of any  privilege  or license,  (ii) to enable the  Guarantor  to
               maintain   self-insurance   or  to   participate   in  any  funds
               established  to cover any  insurance  risks,  (iii) in connection
               with  workmen's  compensation,   unemployment  insurance,  social
               security, any pension or welfare benefit plan or (iv) to share in
               the privileges or benefits  required for companies  participating
               in one or more of the arrangements  described in clauses (ii) and
               (iii) above;

                       (l) Liens on property of the Guarantor  which are granted
               by  the  Guarantor  to  secure  duties  or  public  or  statutory
               obligations or to secure,  or serve in lieu of,  surety,  stay or
               appeal bonds;

                       (m)  rights  reserved  to or  vested in others to take or
               receive any part of any coal,  ore, gas, oil and other  minerals,
               any timber and/or any electric  capacity or energy,  gas,  water,

                                      B-8

<PAGE>

               steam and any other products, developed, produced,  manufactured,
               generated, purchased or otherwise acquired by the Guarantor or by
               others on property of the Guarantor;

                       (n) (i) rights and  interests  of Persons  other than the
               Guarantor   arising  out  of  contracts,   agreements  and  other
               instruments to which the Guarantor is a party and which relate to
               the common ownership or joint use of property; and (ii) all Liens
               on the  interests of Persons other than the Guarantor in property
               owned in common by such  Persons and the  Guarantor if and to the
               extent that the  enforcement  of such Liens  would not  adversely
               affect the  interests of the  Guarantor  in such  property in any
               material respect;

                       (o) any restrictions on assignment and/or requirements of
               any  assignee to qualify as a permitted  assignee  and/or  public
               utility or public service corporation;

                       (p) any Liens  which have been bonded for the full amount
               in dispute or for the  payment of which other  adequate  security
               arrangements have been made;

                       (q) grants, by the Guarantor of easements,  ground leases
               or  rights-of-way  in, upon,  over and/or  across the property or
               rights-of-way  of the  Guarantor  for the purpose of roads,  pipe
               lines,  transmission  lines,  distribution  lines,  communication
               lines, railways, removal of coal or other minerals or timber, and
               other  like  purposes,  or for the  joint or  common  use of real
               property,  rights-of-way,  facilities and/or equipment; provided,
               however,  that no such grant shall  materially  impair the use of
               the  property or  rights-of-way  for the  purposes for which such
               property or rights-of-way are held by the Guarantor;

                       (r) Prepaid Liens;

                       (s) Purchase  Money Liens and any other Liens existing or
               placed upon property at the time of, or within one hundred eighty
               (180) days after, the acquisition  thereof by the Guarantor,  and
               any extensions, renewals and/or replacements of any such Liens to
               secure any refundings,  refinancings  and/or  replacements of the
               indebtedness  secured thereby;  provided,  however,  that no such
               Purchase  Money Lien or other  Lien shall  extend to or cover any
               property of the Guarantor other than (i) the property so acquired
               and  improvements,  extensions and additions to such property and
               renewals,  replacements and substitutions of or for such property
               or any part or parts  thereof  and (ii) with  respect to Purchase
               Money  Liens,  other  property   subsequently   acquired  by  the
               Guarantor;

                       (t)  Liens on  property  of the  Guarantor  which  secure
               indebtedness  for borrowed money which matures less than one year
               from the date of the  issuance or  incurrence  thereof and is not
               extendible  at the  option  of the  issuer,  and any  extensions,
               renewals  and/or  replacements  of any such  Liens to secure  any
               refundings, refinancings and/or replacements of such indebtedness
               by or with similar indebtedness;

                       (u)  Liens   created  or  assumed  by  the  Guarantor  in
               connection  with the issuance of debt  securities the interest on
               which is not  included  in gross  income for  purposes of federal
               income taxation  pursuant to Section 103 of the Internal  Revenue
               Code of 1986, as amended (or any successor provision of law), for
               the purpose of financing, in whole or in part, the acquisition or
               construction  of  property  to be used by the  Guarantor,  to the
               extent that such Lien is required in connection with the issuance
               of such debt securities either by applicable law or by the issuer
               of such debt  securities  or is  otherwise  necessary in order to
               establish or maintain such exclusion  from gross income;  and any
               extensions,  renewals  and/or

                                      B-9
<PAGE>

               replacements   of  any  such  Liens  to  secure  any  refundings,
               refinancings  and/or  replacement  of such debt  securities by or
               with similar securities;

                       (v) Liens securing  indebtedness or lease obligations (i)
               which are related to the  construction or acquisition of property
               not  previously  owned by the Guarantor or (ii) which are related
               to the  financing  of a  project  involving  the  development  or
               expansion of property of the  Guarantor  and (iii) the obligee in
               respect of which has no recourse to the Guarantor or any property
               of the Guarantor other than the property  constructed or acquired
               with the  proceeds of such  transaction  or the project  financed
               with the proceeds of such transaction (or the proceeds thereof);

                       (w) Liens created by the Mortgage and Deed of Trust dated
               September 1, 1945 between the  Guarantor and Irving Trust Company
               (now The Bank of New  York)  and  Richard  H.  West  (Douglas  I.
               MacInnes,  successor),  as Trustees,  as heretofore and hereafter
               supplemented and amended (the  "Mortgage");  and Liens created by
               any other indenture  hereafter executed by the Guarantor pursuant
               to  which  bonds  issued  under  the  Mortgage  are  or are to be
               delivered to the  trustee(s)  under such indenture in a principal
               amount at least equal to the principal  amount of debt securities
               to be secured by such indenture; and

                       (x) in addition to the Permitted Liens defined in clauses
               (a) through  (w) above,  Liens on any  property of the  Guarantor
               (other  than  Excepted  Property)  to  secure   indebtedness  for
               borrowed money (under  circumstances not otherwise  excepted from
               the operation of this Section) in an aggregate  principal  amount
               not  exceeding  2.5% of the total assets of the Guarantor and its
               consolidated  subsidiaries,  as shown on the latest balance sheet
               of the Guarantor and its  consolidated  subsidiaries,  audited by
               independent certified public accountants, dated prior to the date
               of the issuance or incurrence of such indebtedness.

                       "PREPAID LIEN" means any Lien securing indebtedness for
the payment, prepayment or redemption of which there shall have been irrevocably
deposited in trust with the trustee or other  holder of such Lien moneys  and/or
Investment  Securities which (together with the interest  reasonably expected to
be earned from the investment and  reinvestment in Investment  Securities of the
moneys  and/or the  principal of and interest on the  Investment  Securities  so
deposited) shall be sufficient for such purpose; provided, however, that if such
indebtedness is to be redeemed or otherwise prepaid prior to the stated maturity
thereof,  any notice  requisite to such redemption or prepayment shall have been
given in  accordance  with the  instrument  creating  such  Lien or  irrevocable
instructions  to give such notice shall have been given to such trustee or other
holder.  As used  herein,  the term  "Investment  Securities"  means  any of the
following  obligations or securities on which neither the  Guarantor,  any other
obligor on the  Securities  of the Second  Series nor any Affiliate of either is
the obligor: (a) Government  Obligations;  (b) interest bearing deposit accounts
(which may be represented by  certificates  of deposit) in any national or state
bank (which may  include  the  Trustee or any Paying  Agent) or savings and loan
association  which has outstanding  securities rated by a nationally  recognized
rating  organization in either of the two (2) highest rating categories (without
regard  to  modifiers)  for  short  term  securities  or in any of the three (3)
highest  rating   categories   (without  regard  to  modifiers)  for  long  term
securities;  (c) bankers'  acceptances  drawn on and accepted by any  commercial
bank (which may include the Trustee or any Paying  Agent) which has  outstanding
securities rated by a nationally recognized rating organization in either of the
two (2) highest rating  categories  (without regard to modifiers) for short term
securities or in any of the three (3) highest rating categories  (without regard
to  modifiers)  for  long  term  securities;   (d)  direct  obligations  of,  or
obligations  the  principal  of  and  interest  on  which  are   unconditionally
guaranteed  by, any State or Territory  of the United  States or the District of
Columbia, or any political subdivision of any of the foregoing,  which are rated
by a nationally  recognized rating organization in either of the two (2) highest
rating categories  (without regard to modifiers) for short term securities or in
any of the three (3) highest

                                      B-10

<PAGE>

rating  categories  (without regard to modifiers) for long term securities;  (e)
bonds or other  obligations  of any  agency  or  instrumentality  of the  United
States; (f) corporate debt securities which are rated by a nationally recognized
rating  organization in either of the two (2) highest rating categories (without
regard  to  modifiers)  for  short  term  securities  or in any of the three (3)
highest  rating   categories   (without  regard  to  modifiers)  for  long  term
securities;  (g)  repurchase  agreements  with  respect to any of the  foregoing
obligations or securities with any banking or financial  institution  (which may
include the Trustee or any Paying Agent) which has outstanding  securities rated
by a nationally  recognized rating organization in either of the two (2) highest
rating categories  (without regard to modifiers) for short term securities or in
any of the three (3) highest rating categories (without regard to modifiers) for
long term securities;  (h) securities issued by any regulated investment company
(including any  investment  company for which the Trustee or any Paying Agent is
the advisor), as defined in Section 851 of the Internal Revenue Code of 1986, as
amended,  or any successor  section of such Code or successor  federal  statute,
provided that the portfolio of such investment company is limited to obligations
or securities of the character and investment  quality  contemplated  in clauses
(a) through (f) above and repurchase  agreements which are fully  collateralized
by any of such  obligations  or  securities;  and (i) any other  obligations  or
securities  which may  lawfully be  purchased  by the Trustee in its capacity as
such.

                       "PURCHASE MONEY LIEN" means, with respect to any property
being acquired by the Guarantor, a Lien on such

property which

                       (a) is taken or retained by the transferor of such
               property to secure all or part of the purchase price thereof;

                       (b) is  granted  to one or more  Persons  other  than the
               transferor  which, by making advances or incurring an obligation,
               give value to enable the  grantor of such Lien to acquire  rights
               in or the use of such property;

                       (c) is held by a trustee or agent for the  benefit of one
               or more Persons  described  in clause (a) or (b) above,  provided
               that such Lien may be held,  in addition,  for the benefit of one
               or more other Persons which shall have theretofore  given, or may
               thereafter  give,  value to or for the  benefit or account of the
               grantor of such Lien for one or more other purposes; or

                       (d) otherwise constitutes a purchase money mortgage or a
               purchase money security interest under applicable law;

and,  without  limiting the  generality of the  foregoing,  for purposes of this
Guarantee,  the term  Purchase  Money Lien  shall be deemed to include  any Lien
described  above whether or not such Lien (x) shall permit the issuance or other
incurrence of additional indebtedness secured by such Lien on such property, (y)
shall permit the subjection to such Lien of additional property and the issuance
or other  incurrence of additional  indebtedness on the basis thereof and/or (z)
shall have been granted prior to the acquisition of such property,  shall attach
to or otherwise  cover property  other than the property  being acquired  and/or
shall secure  obligations  issued prior and/or subsequent to the issuance of the
obligations delivered in connection with such acquisition.

                                      B-11

<PAGE>

               IN  WITNESS  WHEREOF,  MINNESOTA  POWER,  INC.  has  caused  this
Guarantee  to be  executed  in its  corporate  name by the  manual or  facsimile
signature of its Chairman of the Board of Directors or its  President or any one
of its Vice  Presidents  and its  corporate  seal or a  facsimile  thereof to be
impressed  or  imprinted  hereon,  and the same to be  attested by the manual or
facsimile signature of its Secretary or any one of its Assistant Secretaries.

Dated:  March 30, 2000

                                                  MINNESOTA POWER, INC.

[Corporate Seal]

                                                  By
                                                    ----------------------------

Attest:

------------------------


                                      B-12