<PAGE>

                                                                   EXHIBIT 10(a)


                               FIRST AMENDMENT TO
              FOURTH AMENDED AND RESTATED COMMITTED FACILITY LETTER

                  This First Amendment to Fourth Amended and Restated  Committed
Facility  Letter is dated as of June 19,  2006,  by and among  ALLETE,  INC.,  a
Minnesota corporation (the "COMPANY"),  the banks from time to time party to the
Committed   Facility  Letter  (as  hereinafter   defined)  (each  a  "BANK"  and
collectively the "BANKS") and LASALLE BANK NATIONAL ASSOCIATION, in its capacity
as agent for the Banks (in such capacity, the "AGENT").

                                WITNESSETH THAT:

                  WHEREAS,  the  Company,  the  Banks and the Agent are party to
that certain Fourth Amended and Restated  Committed  Facility Letter dated as of
January 11, 2006 (together with all exhibits, schedules, attachments, appendices
and amendments thereof, the "COMMITTED FACILITY LETTER"); and

                  WHEREAS, the Company has requested that the Committed Facility
Letter be  amended  as set forth  herein  and the  Banks are  agreeable  to such
request on the terms and subject to the conditions set forth herein;

                  NOW,  THEREFORE,  for good  and  valuable  consideration,  the
receipt and sufficiency of which is hereby acknowledged,  the Company, the Banks
and the Agent hereby agree as set forth below.

        1.   The Committed Facility Letter is hereby amended as follows:

                        (a)  Section 4(b) is amended by deleting the proviso at
        the end of clause (ii) thereof and  ending such Section after the  words
        "be continuing";

                        (b)  Section  5(d)  is  amended  by  deleting  the  last
        sentence thereof  in its  entirety and  substituting the  following  new
        sentence therefor:

                  "There has not been, as of the Closing Date, any Material
                  Adverse Change since the date of  such interim  financial
                  statements."; and

                        (c)  Section 7(a) is amended by deleting clause (vii) at
        the end thereof and substituting the semi-colon and word "or"  appearing
        at the end of clause (vi)(5) with a period.

        2.   Except as expressly amended hereby, the Committed  Facility  Letter
and all other  documents  executed in connection  therewith shall remain in full
force and  effect in  accordance  with their  respective  terms.  The  Committed
Facility  Letter,  as amended hereby,  and all rights and powers created thereby
and  thereunder or under such other  documents are in all respects  ratified and
confirmed.  From and after the date hereof,  the Committed Facility Letter shall
be deemed to be  amended  and  modified  as herein  provided  and,  except as so
amended and modified, the Committed Facility Letter shall continue in full force
and effect in accordance


<PAGE>

with its terms and the Committed  Facility  Letter and this  Amendment  shall be
read, taken and construed as one and the same instrument.  On and after the date
hereof the term  "AGREEMENT"  as used in the Committed  Facility  Letter and all
other  references to the  Committed  Facility  Letter in the Committed  Facility
Letter, the other documents executed in connection  therewith and/or herewith or
any other  instrument,  document or writing executed by the Company or any other
person or furnished  to the Agent and/or the Banks by the Company,  or any other
person in connection herewith or therewith, shall be deemed to be a reference to
the Committed Facility Letter as hereby amended.

        3.   The effectiveness of this Amendment is subject to the  satisfaction
of the following conditions precedent:

                        (a)  The Company and each  Bank shall  have executed and
        delivered this Amendment to Agent together with such other documents and
        instruments as Agent may reasonably require;

                        (b)  No Default or Event of Default shall have  occurred
        and be continuing; and

                        (c)  Agent  shall have  received a  certificate  of  the
        Secretary  of the  Company having  attached  an  incumbency  certificate
        showing  the names  and  titles, and  bearing  the  signatures  of,  the
        officers of the Company authorized to execute this Amendment.

        4.   On and as of the date hereof, the Company  represents and  warrants
to the Agent and to the Banks that:

                        (a)  The  representations and  warranties  contained  in
        this Amendment and the Committed Facility Letter are true and correct in
        all material respects, in each case as though made on and as of the date
        hereof, except to the extent such representations and  warranties relate
        solely to an earlier date (and then as of such earlier date); and

                        (b)  Both  before  and   after  giving  effect  to  this
        Amendment, no Default or Event of Default has occurred and is continuing
        or would result from the execution and delivery of this Amendment; and

                        (c)  The  Company  is, and  will be, in  full compliance
        with all of the material  terms, conditions and  all other provisions of
        this Amendment and the Credit Documents; and

                        (d)  This Amendment  has been  duly authorized, executed
        and  delivered on its behalf,  and both the Committed  Facility  Letter,
        both before  being  amended and  supplemented  hereby and as amended and
        supplemented  hereby, and this Amendment constitute its legal, valid and
        binding  obligation  enforceable  against  it in  accordance  with their
        terms,  except to the extent that a remedy or default may be  determined
        by a court of competent  jurisdiction to constitute a penalty and except
        to  the  extent  that

                                      -2-


<PAGE>
        enforceability may be limited by bankruptcy, insolvency, reorganization,
        moratorium or other  similar laws  relating to  creditors'  rights or by
        general principles of equity.

        5.   This Amendment shall be construed in  accordance with and  governed
by the internal laws of the State of Illinois,  without  regard to its conflicts
of laws principles.

        6.   This Amendment may be signed in any number of counterparts, each of
which shall be deemed an original,  but all of which together  shall  constitute
one and the same instrument. This Amendment may also be signed by facsimile, and
any  facsimile  signature  hereto  shall for all  purposes be deemed an original
signature.

        7.   Except as otherwise specified  herein, this Amendment embodies  the
entire  agreement  and  understanding  between  the  Company  and the Banks with
respect to the  subject  matter  hereof  and  supersedes  all prior  agreements,
consents and understandings relating to such subject matter.

        8.   This Amendment shall  be binding  upon and inure to the  benefit of
the Banks and their  successors  and assigns  and the Company and its  permitted
successors and assigns.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


                                      -3-


<PAGE>
                  IN WITNESS WHEREOF, the parties hereto have caused this  First
Amendment to Fourth Amended and  Restated Committed  Facility Letter to be  duly
executed and delivered by their duly authorized  officers as of the day and year
first above written.



THE COMPANY:                    ALLETE, INC., a Minnesota corporation
-----------

                                By:   /s/ James K. Vizanko
                                   ---------------------------------------------
                                Name:   James K. Vizanko
                                     -------------------------------------------
                                Title:  Sr. VP - Finance & CFO
                                      ------------------------------------------



AGENT/BANKS:                    LASALLE BANK NATIONAL ASSOCIATION, in its
-----------                     individual capacity as a Bank and as Agent

                                By:    /s/ David Bond
                                  ----------------------------------------------
                                Name:   David Bond
                                    --------------------------------------------
                                Title:  Senior Vice President
                                     -------------------------------------------



                                By:
                                  ----------------------------------------------
                                Name:
                                    --------------------------------------------
                                Title:
                                     -------------------------------------------



                                      -4-
<PAGE>


                                                                  Signature Page
        First Amendment to Fourth Amended and Restated Committed Facility Letter
                                                                    June 9, 2006

OTHER BANKS:
-----------

                                U.S. BANK NATIONAL ASSOCIATION


                                By:    /s/ Christopher W. Rupp
                                   ---------------------------------------------
                                Name:   Christopher W. Rupp
                                     -------------------------------------------
                                Title:  Vice President
                                      ------------------------------------------


                                WELLS FARGO BANK,
                                NATIONAL ASSOCIATION

                                By:    /s/ Patrick McCue
                                   ---------------------------------------------
                                Name:   Patrick McCue
                                     -------------------------------------------
                                Title:  Vice President & Senior Relationship
                                        Manager
                                        Wells Fargo Bank, National Association
                                      ------------------------------------------


                                JPMORGAN CHASE BANK, N.A.

                                By:   /s/ Gabriel Simon
                                   ---------------------------------------------
                                Name:   Gabriel Simon
                                     -------------------------------------------
                                Title:  AVP
                                      ------------------------------------------


                                THE BANK OF TOKYO - MITSUBISHI, UFJ, LTD.,
                                Chicago Branch

                                By:   /s/ Mathew Ross
                                   ---------------------------------------------
                                Name:   Mathew Ross
                                     -------------------------------------------
                                Title:  Vice President & Manager
                                      ------------------------------------------



                                      -5-