<Page>

                                                                   Exhibit 10.ab

                          MAINE PUBLIC SERVICE COMPANY
                           DEFERRED COMPENSATION PLAN
                              FOR OUTSIDE DIRECTORS

                         DEFERRED COMPENSATION AGREEMENT

     AGREEMENT made this     day of              , between Maine Public Service
Company, a Maine corporation ("Company") and                , a member of the
Company's Board of Directors ("Director").

     WHEREAS, the Company maintains the Maine Public Service Company Deferred
Compensation Plan for Outside Directors ("Plan") to provide directors of the
Company with an opportunity to defer their compensation; and

     WHEREAS, the Director and the Company desire to enter into an agreement
under which the Director shall, pursuant to the terms of the Plan, defer
compensation, subject to the terms, conditions and restrictions set forth
herein;

     NOW, THEREFORE, in consideration of the premises and mutual promises
contained herein, IT IS AGREED:

     1.   Deferral Election. Director hereby elects to defer receipt of the
following amounts which otherwise are payable for services rendered subsequent
to the date of this Agreement in calendar year 2000 and in each calendar year
thereafter.

     [ELECT (i) OR (ii).]

          / /    (i)    all fees (annual retainer, meeting fees and, if
                        applicable, committee chairperson retainer)

          / /    (ii)   % of the annual retainer and % of meeting fees (and, if
                        applicable, committee chairperson retainer)

     Solely for purposes of valuing the amounts deferred, such amounts shall be
deemed invested as follows:

     [ELECT (i), (ii) OR (iii).]

          / /    (i)    entirely in Maine Public Service Company common stock
                        ("Shares")

          / /    (ii)   entirely in five-year U.S. Treasury notes ("Treasuries")

          / /    (iii)         % in Shares and      % in Treasuries

<Page>

     2.   Deferral Account. The Company shall establish an account which shall
be identified as the Director's "Deferral Account" (hereinafter "Account") and
shall adjust the Account as follows:

          (a)    At the end of each calendar month for which fees are otherwise
                 payable, credit such Account:

                 (i)    to the extent it is deemed invested in Treasuries, with
                        the amount, if any, deferred during such period;

                 (ii)   to the extent it is deemed invested in Shares, with the
                        number of Shares that could have been purchased with the
                        amounts, if any, deferred during such period, at the
                        fair market value of a Share on the day (or days) the
                        fees would have been paid in the absence of a deferral
                        election; and

          (b)    As of the first day of each calendar month:

                 (i)    debit such Account by the amount or by the number of
                        Shares, if any, paid to the Director or the Director's
                        designated beneficiary during the preceding calendar
                        month;

                 (ii)   credit such Account after making the debit adjustment
                        described in subsection (i):

                        (A)  to the extent it is deemed invested in Treasuries,
                             with interest on the balance as of the first day of
                             the preceding month at the rate paid on Treasuries
                             on the first day of the calendar year in which the
                             interest is to be credited;

                        (B)  to the extent it is deemed invested in Shares, with
                             any dividends paid during such period on the Shares
                             credited to the Account as of the first day of the
                             preceding month; and

                        to the extent such Account is deemed invested in Shares,
                        adjust the number of Shares to reflect any stock split
                        or stock dividend.

     3.   PAYMENT TO DIRECTOR. The amount credited to the Director's Account
shall be paid to the Director in the following manner:

     [ELECT (i) OR (ii) ONLY IF THIS IS THE FIRST DEFERRED COMPENSATION
     AGREEMENT THAT YOU HAVE EXECUTED UNDER THE PLAN.]

<Page>

     / /  (i)    a lump sum

     / /  (ii)   substantially equal consecutive monthly installments over a
                 period of (    ) years (DESIGNATE NUMBER OF YEARS NOT EXCEEDING
                 TEN).

     Payment shall be made on or shall commence with the first day of the month
following the date on which the Director ceases to serve on the Company's Board
of Directors.

     4.   PAYMENT TO BENEFICIARY. The amount credited. to the Director's Account
at the time of the Director's death under this Agreement and all prior deferred
compensation agreements executed by the Director under the Plan shall be paid to
the Director's designated beneficiary in the following manner:

     [ELECT (i) OR (ii) ONLY IF THIS IS THE FIRST DEFERRED Compensation
     Agreement that you have executed under the Plan or you wish to change a
     prior election.]

     / /  (i)    a-lump sum

     / /  (ii)   substantially equal consecutive monthly installments over a
                 period of ------------------(-----------) years (DESIGNATE
                 NUMBER OF YEARS NOT EXCEEDING TEN) unless payment previously
                 commenced in accordance with Section 3 of this Agreement, in
                 which event payment shall continue to be made in substantially
                 equal consecutive monthly installments over the remaining term
                 that installments were to be paid in accordance with such
                 section.

     Payment shall be made or commence as soon as practicable following the date
of death, unless payment is continuing pursuant to Section 3 of this Agreement.

     5.   DESIGNATION OF BENEFICIARY. The Director may from time to time, by
completing and signing a form furnished by the Company, designate any person or
persons, who may be designated concurrently, contingently or successively, the
Director's estate, or any trust or trusts created by the Director, to receive
amounts which are payable under this Agreement to the Director's designated
beneficiary or beneficiaries. Each beneficiary designation shall revoke all
prior designations and will be effective only when filed in writing with the
Committee appointed to administer the Plan. If the Director fails to designate a
beneficiary or if a beneficiary dies before the date of the Director's death and
no contingent beneficiary has been designated, then the amounts which are
payable as aforesaid shall be paid to the Director's estate or other successor
in interest.

     6.   ADMINISTRATION. The members of the Committee appointed pursuant to
Section 7 of the Plan (the "Committee") shall have the responsibility of
construing and interpreting this

<Page>

Agreement and the Plan. The determinations and conclusions of the Committee
shall be binding on the parties hereto.

     7.   AMENDMENT. This Agreement, excluding Section 1, may be amended by
written agreement of the Company and the Director. Section 1 may not be amended.

     8.   TERMINATION. This Agreement shall terminate upon the earlier of (i)
the Director's delivery to the Committee of a written notice of termination, or
(ii) termination of the Plan. In the event of termination of the Agreement, the
Company shall continue to hold the amounts deferred hereunder until said amounts
become payable as provided herein.

     9.   MISCELLANEOUS.

          (a)    UNSECURED PROMISE. This Agreement shall not be construed to
     create or require the Company to create a trust of any kind to fund the
     amounts payable hereunder. To the extent the Director or any other person
     acquires a right to receive payments from the Company, such right shall be
     no greater than the right of any unsecured general creditor of the Company.

          (b)    ASSIGNMENT. The right of the Director or any other person to
     payments under this Agreement shall not be subject to alienation,
     assignment, garnishment, attachment, execution or levy of any kind, and any
     attempt to cause such payments to be so subject shall not be recognized by
     the Company.

          (c)    CONTINUED SERVICE AS A DIRECTOR. This Agreement does not give
     the Director any right to be retained in the service of the Company or any
     of its subsidiaries.

          (d)    PLAN PROVISIONS INCORPORATED BY REFERENCE. All of the
     applicable terms and restrictions of the Plan are hereby incorporated by
     reference, and shall have the same force and effect as if they were
     separately restated herein.

          (e)    HEADINGS. All captions or headings contained herein are for
     convenience only and shall not be deemed part of the Agreement.

          (f)    GOVERNING LAW. This Agreement shall be construed and enforced
     in accordance with Maine law.

          (f)    SEVERABILITY. In the event that any provision of this Agreement
     shall be held invalid, it shall not affect the validity of the remainder of
     the Agreement.

          (g)    ENTIRE AGREEMENT. This Agreement contains the entire
     understanding of the parties and all prior representations, promises or
     statements are merged herein.

          (h)    BINDING AGREEMENT. This Agreement shall be binding upon and
     inure to

<Page>

     the benefit of the Company, its successors and assigns, and the Director
     and the Director's heirs, executors, administrators and legal
     representatives.

     IN WITNESS WHEREOF, the Company has caused this Agreement to be executed by
its duly authorized officer, and the Director has executed this Agreement as of
the date first above written.

                                        MAINE PUBLIC SERVICE COMPANY ("Company")


                                        By
                                           -------------------------------------
                                             Its


                                        Director
                                                 -------------------------------


     Persons who have Executed the above Deferred Compensation Agreement:

<Table>
<Caption>
     Individual                                           Date executed
     ----------                                           -------------
     <S>                                                    <C>
     David N. Felch                                         01/24/2003
     Lance Smith                                            12/06/2002
     Robert E. Anderson                                     01/07/2000
     Richard G. Daigle                                      01/07/2000
</Table>