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                          MAINE YANKEE ATOMIC POWER COMPANY


                                          TO


                          THE FIRST NATIONAL BANK OF BOSTON,

                                                  Trustee


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


                            SEVENTH SUPPLEMENTAL INDENTURE

                               Dated as of May 15, 1993

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


                           RELATING TO FIRST MORTGAGE BONDS


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


           Additional Issue:  $25,000,000 of First Mortgage Bonds, Series F
                            (Sinking Fund) 6.89% Due 2008.





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                    THIS SEVENTH SUPPLEMENTAL INDENTURE, dated as of
          May 15, 1993, between MAINE YANKEE ATOMIC POWER COMPANY, a Maine
          corporation, with its principal office in Augusta, Maine
          (hereinafter generally referred to as the Company), and THE FIRST
          NATIONAL BANK OF BOSTON, a national banking association, with its
          principal office at 100 Federal Street, Boston, Massachusetts
          02110, as trustee under the First Mortgage Indenture, as
          supplemented, referred to in the first recital hereof (the
          Trustee from time to time under said First Mortgage Indenture, as
          supplemented, being hereinafter generally referred to as the
          Trustee).

                    WHEREAS, the Company heretofore duly executed and
          delivered to Old Colony Trust Company, as Trustee, its First
          Mortgage Indenture dated as of November 1, 1970 (hereinafter
          generally referred to as the Original Indenture, and sometimes
          referred to, with each and every other instrument, including this
          Supplemental Indenture, which the Company, pursuant to the
          provisions thereof, may execute with the Trustee and which is
          therein stated to be supplemental to the Original Indenture, as
          the Indenture), recorded in the Office of the Secretary of State
          of Maine, File No. 146534, Lincoln County Registry of Deeds, Book
          678, Page 1, and Sagadahoc County Registry of Deeds, Book 373,
          Page 777, to which this instrument is supplemental, and the
          Company heretofore duly executed and delivered to The First
          National Bank of Boston, as successor Trustee, an indenture, 
          dated as of March 1, 1971, supplemental to and in confirmation of
          the Original Indenture, recorded in the Office of the Secretary
          of State of Maine, File No. 152116, Lincoln County Registry of
          Deeds, Book 686, Page 48, and Sagadahoc County Registry of Deeds,
          Book 374, Page 1003, a second indenture, dated as of January 1,
          1973, supplemental to and in confirmation of the Original
          Indenture, as theretofore supplemented, recorded in the Office of
          the Secretary of State of Maine, File No. 207526, Lincoln County
          Registry of Deeds, Book 757, Page 247, and Sagadahoc County
          Registry of Deeds, Book 388, Page 380, a third indenture, dated
          as of February 15, 1984, supplemental to and in confirmation of
          the Original Indenture, as theretofore supplemented, recorded in
          the Office of the Secretary of State of Maine, File No. 588974,
          Lincoln County Registry of Deeds, Book 1179, Page 207, and
          Sagadahoc County Registry of Deeds, Book 658, Page 33, a fourth
          indenture, dated as of April 1, 1986, supplemental to and in
          confirmation of the Original Indenture, as theretofore
          supplemented, recorded in the Office of the Secretary of State of
          Maine, File No. 679327, Lincoln County Registry of Deeds, Book
          1300, Page 273, and Sagadahoc County Registry of Deeds, Book 748,
          Page 92, a fifth indenture, dated as of March 1, 1991,
          supplemental to and in confirmation of the Original Indenture, as
          theretofore supplemented, recorded in the office of the Secretary
          of State of Maine, File No. 927150, Lincoln County Registry of
          Deeds, Book 1678, Page 101, and Sagadahoc County Registry of
          Deeds, Book 1052, Page 127 and a sixth indenture, dated as of
          January 15, 1993, supplemental to and in confirmation of the
          Original Indenture, as theretofore supplemented, recorded in the
          office of the Secretary of State of Maine, File No. 1015944,
          Lincoln County Registry of Deeds, Book 1848, Page 201, and
          Sagadahoc County Registry of Deeds, Book 1180, Page 103, whereby
          all the properties of the Company whether then owned or
          thereafter acquired, with certain reservations, exceptions and
          exclusions fully set forth in the Original Indenture, as
          heretofore supplemented, were given, granted, bargained, sold,
          transferred, assigned, pledged, mortgaged, warranted, conveyed
          and confirmed to the Trustee, its successors and assigns, in
          trust upon the terms and conditions set forth therein to secure
          bonds of the Company issued and to be issued thereunder, and for
          other purposes more particularly specified therein; and

                    WHEREAS, Section 16.01 of the Original Indenture
          provides that the Company, when authorized by a resolution of the
          Board of Directors of the Company (or of any committee of said
          Board, however designated, authorized to exercise the powers of
          said Board in the premises), and the Trustee may from time to
          time enter into an indenture or indentures supplemental to the
          Original Indenture for the following purposes, among others:
          assigning, conveying, mortgaging, pledging, transferring and
          setting over additional property unto the Trustee (Section
          16.01(a)); and providing the terms and conditions of any series
          of bonds other than the bonds of Series A (Section 16.01(c)); and

                    WHEREAS, the Board of Directors of the Company (through
          the duly authorized Finance Committee of said Board) has
          authorized the execution of this Supplemental Indenture and the
          delivery hereof to the Trustee; and 

                    WHEREAS, in all other respects the terms, conditions
          and provisions of subsections (a) and (c) of Section 16.01 have
          been complied with; and 

                    WHEREAS, for its lawful corporate purposes, the Company
          has duly authorized the creation of a new series of its bonds to
          be issued under the Indenture, to be known as First Mortgage
          Bonds, Series F (Sinking Fund) 6.89% Due 2008 (hereinafter
          sometimes called the bonds of Series F or the Series F Bonds),
          and has duly authorized the execution and delivery of this
          Supplemental Indenture; and

                    WHEREAS, the form of the Series F Bonds, which are to
          be issued only in fully registered form without coupons, and the
          form of the Trustee's certificate of authentication to be
          executed on the Series F Bonds, are to be substantially in the
          following forms, respectively:

          

                               (FORM OF SERIES F BOND)

                                  (1933 Act Legend)

          No. FR ___________                                     $_________


                          MAINE YANKEE ATOMIC POWER COMPANY

             First Mortgage Bond, Series F (Sinking Fund) 6.89% Due 2008

                    Maine Yankee Atomic Power Company, a Maine corporation
          (hereinafter called the Company), for value received, hereby
          promises to pay to ____________________________________ or
          registered assigns, the principal sum of ___________________
          Dollars ($_________) at the principal office of The First
          National Bank of Boston (hereinafter called the Trustee, which
          term shall include its successors in the trusts hereinafter
          referred to) in the City of Boston, Commonwealth of Massachusetts
          (or at the principal office of its then successor Trustee) or, at
          the option of the registered owner hereof, at the principal
          office of any designated paying agent in the Borough of
          Manhattan, City and State of New York, on May 1, 2008 and to pay
          interest thereon from the May 1 or November 1, as the case may
          be, next preceding the date hereof (or from the date hereof if
          such date be either of said dates) to which interest has been
          paid on this bond, or, in the case of interest payable on
          November 1, 1993, from the date on which any bonds of Series F
          were first issued, at the rate per annum specified in the title
          of this bond, on May 1 and November 1 in each year, at the
          principal office of the Trustee or, at the option of the
          registered owner hereof, at the principal office of any such
          paying agent, until the principal hereof shall have been paid in
          full; such interest payable on any May 1 or November 1 shall
          (subject to certain exceptions provided in the Indenture
          mentioned below) be paid to the person in whose name this bond,
          or the bond in exchange or substitution for which this bond shall
          have been issued, shall have been registered at the close of
          business on the April 15 or October 15, as the case may be, next
          preceding such May 1 or November 1.  Interest shall be payable on
          any overdue payment of principal (including any overdue
          redemption), premium and (to the extent legally enforceable)
          interest, at a rate per annum from time to time equal to the
          greater of (i) 7.89% or (ii) the rate of interest publicly
          announced by Morgan Guaranty Trust Company of New York from time
          to time in New York City as its Prime Rate (but only to the
          extent allowable under the Order entered on May 3, 1993 by the
          Maine Public Utilities Commission in Docket No. 93-081), accruing
          at such rate from the date on which such payment was due and
          unpaid.  Both principal and premium, if any, and interest shall
          be paid in coin or currency of the United States of America
          which, at the time of payment, is legal tender for public and
          private debts.  Notwithstanding any provision to the contrary in
          this bond or in the Indenture mentioned below, Section 5.1 of the
          Bond Purchase Agreement dated as of June 1, 1993 pursuant to
          which the bonds of Series F were initially issued (hereinafter
          called the Bond Purchase Agreement) shall govern payments with
          respect to the bonds of Series F to the bondholders referred to
          in said Section 5.1, and Section 6.3 of said Bond Purchase
          Agreement shall govern the replacement of bonds of Series F to
          the extent set forth in said Section 6.3.  A copy of said Bond
          Purchase Agreement is on file at the principal office of the
          Trustee.

                    This bond is one of a duly authorized issue of First
          Mortgage Bonds of the Company, the aggregate principal amount of
          which is not limited except by law, to be issued in series with
          distinctive designations, the series of which this bond is one,
          designated as Series F, being the sixth series and limited to an
          aggregate principal amount of Twenty-Five Million Dollars
          ($25,000,000), all bonds of all series, including the bonds of
          Series F, to be issued under and secured by a certain First
          Mortgage Indenture dated as of November 1, 1970 by and between
          the Company and the Trustee, as supplemented (said First Mortgage
          Indenture, together with all other indentures supplemental
          thereto to which the Trustee shall be a party, being hereinafter
          referred to as the Indenture), to which reference is hereby made
          for a description of the mortgaged and pledged property, the
          nature and extent of the security and benefit thereof, the terms
          and conditions under which bonds may be issued and secured, the
          rights and remedies under the Indenture of the bondholders and
          the rights and obligations under the Indenture of the Company and
          the Trustee.  Executed counterparts of the Indenture are on file
          at the principal office of the Trustee.

                    The Indenture may, with the consent of the holders of
          not less than sixty-six and two-thirds per cent (66-2/3%) in
          principal amount of the bonds of all series then issued and
          outstanding, and as stated therein, be modified in certain
          respects upon the conditions and in the manner provided therein,
          but, among other restrictions, no such modification shall affect
          or impair the obligation of the Company in respect of the
          principal of and premium, if any, and interest on this bond.

                    In the event of certain defaults, the principal of this
          bond may be declared or may become due and payable prior to
          maturity upon the conditions and in the manner provided in the
          Indenture.

                    This bond is transferable on the bond register, upon
          surrender hereof at the principal office of the Trustee, in the
          City of Boston, Massachusetts, or at the office or agency to be
          maintained by the Company in the Borough of Manhattan, City and
          State of New York, and upon compliance with the conditions
          prescribed in the Indenture and accompanied by a written
          instrument of assignment in proper form, duly executed by the
          registered owner in person or by duly authorized attorney, and
          thereupon a new bond or bonds of the same series and for a like
          aggregate principal amount of authorized denominations will be
          issued in the name of the transferee.

                    The Company, the Trustee, any authenticating agent, any
          paying agent and any registrar may deem and treat the registered
          holder hereof as the absolute owner of this bond (whether or not
          this bond shall be overdue and notwithstanding any notice of
          ownership or writing hereon made by anyone other than the Company
          or any registrar), for the purpose of receiving payment hereof or
          on account hereof or interest hereon (subject to the provisions
          of the first paragraph hereof) and for all other purposes, and
          neither the Company, the Trustee, any authenticating agent, any
          paying agent nor any registrar shall be affected by any notice to
          the contrary.

                    The bonds of Series F consist of fully registered bonds
          without coupons in the denominations of one thousand dollars
          ($1,000) and multiples thereof.  This bond, singly or with other
          bonds of the same series and registered in the same name, may be 
          exchanged for one or more bonds of the same series and for a like
          aggregate principal amount in authorized denominations.  All
          bonds to be so exchanged shall be surrendered for that purpose at
          the principal office of the Trustee, or at the office or agency
          to be maintained by the Company in the Borough of Manhattan, City
          and State of New York, and, if required by the Trustee,
          accompanied by written instruments of assignment in proper form,
          duly executed by the registered owner in person or by duly
          authorized attorney.

                    The bonds of Series F are subject to redemption (a) at
          any time in whole or from time to time in part (in multiples of
          $1,000), by the Company at its option, or (b) in whole or in part
          by operation of various provisions of the Indenture (including,
          without limitation, provisions establishing the sinking fund for
          the bonds of Series F) at the time or times specified in such
          provisions, in each instance by the payment of the applicable
          redemption price specified below and accrued interest to the date
          fixed for redemption on the principal amount of the bonds being
          redeemed.  The applicable redemption price shall be:

                    (i)  100% of the principal amount of the bonds being
               redeemed (constituting the "Special Redemption Price"), if
               the bonds are redeemed by the use of sinking fund and
               certain insurance, release or other moneys held by the
               Trustee, as more fully set forth in the Indenture, and 

                   (ii)  otherwise, 100% of the Called Principal (as
               defined below) plus the Yield-Maintenance Amount applicable
               thereto (calculated as set forth below).

                    "Yield-Maintenance Amount" shall mean, with respect to
          any bond of Series F, a premium equal to the excess, if any, of
          the Discounted Value of the Called Principal of such bond over
          the sum of (i) such Called Principal plus (ii) interest accrued
          thereon as of the Settlement Date (including interest due on such
          date) with respect to such Called Principal (provided, that the
          Yield-Maintenance Amount shall in no event be less than zero).

                    "Business Day" shall mean any day other than a
          Saturday, a Sunday or a day on which commercial banks in New York
          City are required or authorized to be closed.

                    "Called Principal" shall mean, with respect to any bond
          of Series F, the principal of such bond that is to be redeemed.

                    "Discounted Value" shall mean, with respect to the
          Called Principal of any bond of Series F, the amount obtained by
          discounting all Remaining Scheduled Payments with respect to such
          Called Principal from their respective scheduled due dates to the
          Settlement Date with respect to such Called Principal, in
          accordance with accepted financial practice and at a discount
          factor (applied on a semiannual basis) equal to the sum of
          (i) the Reinvestment Yield with respect to such Called Principal,
          plus (ii) fifty (50) basis points.

                    "Reinvestment Yield" shall mean, with respect to the
          Called Principal of any bond of Series F, the yield to maturity
          implied by (i) the yields reported, as of 10:00 A.M. (New York
          City time) on the third Business Day next preceding the
          Settlement Date with respect to such Called Principal, on the
          display designated as "Page 678" on the Telerate Service (or such
          other display as may replace Page 678 on the Telerate Service)
          for actively traded U.S. Treasury securities having a maturity
          equal to the Remaining Average Life of such Called Principal as
          of such Settlement Date, or if such yields shall not be reported
          as of such time or the yields reported as of such time shall not
          be ascertainable, (ii) the Treasury Constant Maturity Series
          yields reported, for the latest day for which such yields shall
          have been so reported as of the third Business Day next preceding
          the Settlement Date with respect to such Called Principal, in
          Federal Reserve Statistical Release H.15 (519) (or any comparable
          successor publication) for actively traded U.S. Treasury
          securities having a constant maturity equal to the Remaining
          Average Life of such Called Principal as of such Settlement Date. 
          Such implied yield shall be determined, if necessary, by
          (a) converting U.S. Treasury bill quotations to bond-equivalent
          yields in accordance with accepted financial practice and
          (b) interpolating linearly between yields reported for various
          maturities.

                    "Remaining Average Life" shall mean, with respect to
          the Called Principal of any bond of Series F, the number of years
          (calculated to the nearest one-twelfth year) obtained by dividing
          (i) such Called Principal into (ii) the sum of the products
          obtained by multiplying (a) each Remaining Scheduled Payment of
          such Called Principal (but not of interest thereon) by (b) the
          number of years (calculated to the nearest one-twelfth year)
          which will elapse between the Settlement Date with respect to
          such Called Principal and the scheduled due date of such
          Remaining Scheduled Payment.

                    "Remaining Scheduled Payments" shall mean, with respect
          to the Called Principal of any bond of Series F, all payments of
          such Called Principal and interest thereon that would be due on
          or after the Settlement Date with respect to such Called
          Principal if no payments of such Called Principal were made prior
          to their scheduled due dates.

                    "Settlement Date" shall mean, with respect to the
          Called Principal of any bond of Series F, the date on which such
          Called Principal is to be redeemed.

                    Notice of redemption shall be given by mail, first
          class postage prepaid, to the holders of the bonds of Series F to
          be redeemed not less than thirty (30) days prior to the date
          fixed for redemption, at their last addresses as they shall
          appear on the register, or otherwise as provided in the
          Indenture.  In the case of any redemption of bonds of Series F
          for which the applicable redemption price has as a component a
          Yield-Maintenance Amount, which will be determined prior to the
          date fixed for redemption but subsequent to the date of the
          giving of such notice, the notice of such redemption shall
          sufficiently specify the applicable redemption price if it shall
          state that such redemption price is equal to 100% of the
          principal of such bond specified in such notice to be redeemed,
          plus a Yield-Maintenance Amount calculated as set forth in the
          bonds of Series F.  The Company, on or prior to the date fixed
          for redemption, will deliver or cause to be delivered to each
          holder of a bond of Series F called for redemption a written
          statement showing the calculation of the Yield-Maintenance Amount
          and the redemption price determined on the basis thereof, which
          statement shall be accompanied by a certification verifying the
          accuracy of the calculations from The Prudential Insurance
          Company of America (or any corporate affiliate thereof) as long
          as The Prudential Insurance Company of America (or any corporate
          affiliate thereof) holds any bond of Series F.  Otherwise, said
          certification verifying the accuracy of the calculations shall be
          prepared by Kidder, Peabody & Co. Incorporated or such other
          investment banking firm of national reputation as shall be
          designated by the Company and approved in writing by holders of
          at least 25% in principal amount of the bonds of Series F then
          outstanding.

                    In case of the call for redemption of less than the
          whole principal amount of this bond, upon payment of the
          redemption price to the registered owner hereof and surrender of
          this bond, there shall be issued to such registered owner another
          bond of Series F in principal amount equal to the unredeemed
          balance hereof.  

                    Section 9.7 of the Bond Purchase Agreement is a
          bondholders' redemption agreement (within the meaning of Section
          8.02 of the Indenture) among the holders of the bonds of Series
          F, satisfactory to and a copy of which is on file with the
          Trustee, that provides for the method that shall be followed by
          the Trustee in selecting bonds or parts of bonds for redemption
          in the event such redemption is a redemption of a part only of
          the bonds of Series F.  By acceptance hereof, the holder hereof
          is deemed to have executed, and is bound by the terms of, the
          Bond Purchase Agreement.

                    No recourse upon any obligation contained in this bond
          or in the Indenture or otherwise shall be had against any
          incorporator or any officer, director or stockholder, past,
          present or future, of the Company or any successor corporation,
          such personal liability of every kind being expressly waived.

                    This bond shall not be valid or obligatory for any
          purpose or entitled to any security or benefit under the
          Indenture until the certificate of authentication hereon shall
          have been signed by or on behalf of the Trustee.

                    IN WITNESS WHEREOF, Maine Yankee Atomic Power Company
          has caused this bond to be executed in its name by its President
          or one of its Vice Presidents by his signature or a facsimile
          thereof, and its corporate seal or a facsimile thereof to be
          affixed hereto or imprinted hereon and attested by the signature
          or facsimile signature of its Secretary or one of its Assistant
          Secretaries.

          Dated ____________________

                                        MAINE YANKEE ATOMIC POWER COMPANY



                                        By ________________________________





          [CORPORATE SEAL]


          Attest:



          _____________________________


          

                       (FORM OF CERTIFICATE OF AUTHENTICATION)

                    This bond is one of the bonds of Series F referred to
          in the within-mentioned Indenture.

                                   THE FIRST NATIONAL BANK OF BOSTON,
                                                              Trustee

                                   By ____________________________________
                                             Authorized Signatory

                                   or

                                      _____________________________________
                                             as Authenticating Agent
                                                  for the Trustee


                                   By _____________________________________
                                               Authorized Officer


                                 (FORM OF ASSIGNMENT)

                    For value received the undersigned hereby sell(s),
          assign(s) and transfer(s) unto



          ________________________________________________
                    Please Insert Social Security or Other
                       Identifying Number of Assignee

          the within bond of Maine Yankee Atomic Power Company and all
          rights thereunder, hereby irrevocably constituting and appointing 
                                              attorney to transfer said
          bond on the register of the Company, with full power of
          substitution in the premises.

                    Dated:

          Notice:  The signature to this assignment must correspond with
          the name as written upon the face of the within bond in every
          particular, without alteration or enlargement or any change
          whatever.

                    AND, WHEREAS, all acts and things necessary to make the
          Series F Bonds, when authenticated by the Trustee and issued as
          in this Supplemental Indenture provided, the valid, binding and
          legal obligations of the Company, and to constitute the Original
          Indenture, as heretofore supplemented and as supplemented by this
          Supplemental Indenture, a valid first mortgage and deed of trust
          to secure the payment of the principal of, premium, if any, and
          interest on all bonds issued thereunder, have been done and
          performed.

                    NOW, THEREFORE, in consideration of the premises, and
          of the acceptance and purchase of the bonds by the holders
          thereof, and of the sum of One Dollar duly paid by the Trustee to
          the Company, and of other good and valuable consideration, the
          receipt whereof is hereby acknowledged, and in confirmation of
          and supplementing the Original Indenture, as heretofore
          supplemented, and for the purpose of securing the due and
          punctual payment of the principal of and premium, if any, and
          interest on the bonds issued and to be issued under the
          Indenture, and for the purpose of securing the faithful
          performance and observance of all covenants and conditions
          hereinafter and in the Original Indenture, as heretofore
          supplemented, set forth, the Company has executed and delivered
          this Supplemental Indenture and by these presents does give,
          grant, bargain, sell, transfer, assign, pledge, mortgage,
          warrant, convey and confirm unto The First National Bank of
          Boston, as Trustee, as herein provided, and its successor or
          successors in the trust created by the Indenture, and to its or
          their assigns, forever, all and singular the plants, rights,
          permits, franchises, easements and property, real, personal and
          mixed, now owned or hereafter acquired by the Company, together
          with the rents, issues and profits thereof, in all cases not
          specifically reserved and excepted, and whether now owned or
          hereafter acquired by the Company; including, without limiting
          the generality of the foregoing, all property, except such as may
          have been released by the Trustee or sold or disposed of as
          permitted by the provisions of the Original Indenture, as
          heretofore supplemented, specifically described or referred to in
          Schedule A to the Original Indenture, as heretofore supplemented,
          and in Schedule A to the Sixth Supplemental Indenture, dated as
          of January 15, 1993 (the "Sixth Supplemental Indenture").

                    AND TOGETHER WITH all and singular the now-existing and
          hereafter-acquired rights, privileges, tenements, hereditaments
          and appurtenances belonging to or in any wise appertaining in and
          to the aforesaid property or any part thereof, with all reversion
          and reversions, remainder and remainders and, subject to the
          provisions of Article IX of the Original Indenture, as heretofore
          supplemented, all rents, revenues, earnings, interest, dividends,
          royalties, issues, income and profits thereof, and all the
          estate, right, title, interest and claims whatsoever, at law as
          well as in equity, which the Company now has or may hereafter
          acquire, in and to all and every part of the foregoing, it being
          the intention to include in the Indenture and to subject to the
          lien of the Indenture all land, interests in land, real estate,
          physical assets, other property and interests in property and
          franchises, whether now owned by the Company or which it may
          hereafter acquire, and wherever situated, as if the same were now
          owned by the Company and were specifically described and conveyed
          by the Indenture, except as hereinafter specified.

                    SUBJECT, HOWEVER, (1) to Permitted Liens as that term
          is defined in Article I of the Original Indenture, as heretofore
          supplemented; (2) as to the property specifically described or
          referred to in Schedule A to the Original Indenture, as
          heretofore supplemented, to the liens, charges, encumbrances,
          reservations, exceptions, exclusions, restrictions, conditions,
          limitations, covenants and interests, if any, set forth or
          referred to in said Schedule A; and (3) as to the property
          specifically described in Schedule A to the Sixth Supplemental
          Indenture, to the reservations, exceptions and exclusions set
          forth in said Schedule A.

                    AND SUBJECT FURTHER, as to all hereafter-acquired
          property, to all defects and limitations of title and to all
          liens, charges, encumbrances, reservations, restrictions,
          conditions, limitations, covenants, interests and exceptions
          existing at the time of such acquisition.

                    BUT SPECIFICALLY RESERVING, EXCEPTING AND EXCLUDING (as
          the same were reserved, excepted and excluded from the lien of
          the Original Indenture, as heretofore supplemented) from the
          Indenture, and from the grant, conveyance, mortgage, transfer,
          pledge and assignment herein contained, (i) all right, title and
          interest of the Company, now owned or hereafter acquired, in and
          to the properties and rights specified in subclauses (a) to (j),
          both inclusive, of the granting clauses, on pages 9 and 10 of the
          Original Indenture, and (ii) the rights and interests reserved in
          the three paragraphs of the granting clauses, on pages 10 and 11
          of the Original Indenture, next succeeding the paragraph
          containing the above-mentioned subclauses.

                    TO HAVE AND TO HOLD all said plants, rights, permits,
          franchises, easements and property hereby conveyed, assigned,
          pledged or mortgaged, or intended so to be, unto the Trustee, its
          successor or successors in trust, and to its and their assigns
          forever.

                    BUT IN TRUST, NEVERTHELESS, for the equal pro rata
          benefit, security and protection of the holders from time to time
          of all bonds (and their appurtenant coupons, if any) outstanding
          under the Indenture, without any priority of any one bond or
          coupon over any other (except as provided in Section 6.02 of the
          Original Indenture, as heretofore supplemented, and except as any
          sinking or other fund, established in accordance with the
          Indenture, may afford additional special security for the bonds
          of any particular series), and upon the trusts and subject to the
          conditions herein set forth.

                    PROVIDED, HOWEVER, and these presents are upon the
          condition, that if the Company shall pay or cause to be paid or
          make appropriate provisions for the payment unto the holders of
          the bonds and any appurtenant coupons of the principal, premium,
          if any, and interest to become due thereon at the times and in
          the manner stipulated therein, and shall pay or cause to be paid
          all other sums payable under the Indenture by the Company, then
          the Indenture and the estate and rights hereby granted shall,
          pursuant to the provisions of Article XII of the Original
          Indenture, as heretofore supplemented, cease, determine and be
          void, but otherwise shall be and remain in full force and effect.

                    AND IT IS HEREBY COVENANTED, DECLARED AND AGREED, upon
          the trusts and for the purposes aforesaid, as set forth in the
          following covenants, agreements, conditions and provisions, viz:

                    SECTION 1.  Title and Terms of Series F Bonds.  There
          shall be a series of bonds designated "First Mortgage Bonds,
          Series F (Sinking Fund) 6.89% Due 2008".  The Series F Bonds
          shall be limited in aggregate principal amount to $25,000,000,
          shall be issuable only as fully registered bonds without coupons
          and shall be issued substantially in the form hereinbefore set
          forth.  The Series F Bonds shall mature on May 1, 2008, and may
          be issued in denominations of $1,000 and any multiple thereof.

                    The Series F Bonds shall bear interest, until payment
          of the principal thereof has been made or duly provided for, at
          the rate per annum specified in the title of the Series F Bonds,
          payable semi-annually on May 1 and November 1 in each year,
          commencing on November 1, 1993.  Interest shall be payable on any
          overdue payment of principal (including any overdue redemption),
          premium and (to the extent legally enforceable) interest, at a
          rate per annum from time to time equal to the greater of (i)
          7.89% or (ii) the rate of interest publicly announced by Morgan
          Guaranty Trust Company of New York from time to time in New York
          City as its Prime Rate (but only to the extent allowable under
          the Order entered on May 3, 1993 by the Maine Public Utilities
          Commission in Docket No. 93-081), accruing at such rate from the
          date on which such payment was due and unpaid.

                    Each bond of Series F shall be dated the date of its
          authentication and interest shall be payable on the principal
          represented thereby from the interest payment date next preceding
          the date thereof to which interest has been paid, unless the date
          thereof is an interest payment date to which interest has been
          paid, in which case such interest shall be payable from such
          date, or unless the date thereof is prior to the first interest
          payment date, in which case such interest shall be payable from
          the date on which any bonds of Series F were first issued;
          provided, however, that interest shall be payable on each bond of
          Series F authenticated between an interest payment date and the
          record date therefor as set forth in this Section, and provided,
          further, that if the Company shall default in the payment of the
          interest due on such interest payment date, any bond of Series F
          so authenticated shall bear interest from the May 1 or
          November 1, as the case may be, next preceding the date of such
          bond to which interest has been paid (or, in case no interest has
          been paid on such bond of Series F, from the date on which any
          bonds of Series F were first issued).

                    Interest on any Series F Bond shall be paid to the
          person in whose name such bond (or notwithstanding the
          cancellation thereof, the bond in exchange or substitution for
          which such bond shall have been issued) is registered at the
          close of business on the applicable record date; provided,
          however, that if the Company shall default in the payment of the
          interest due on any interest payment date on the principal
          represented by any Series F Bond, such defaulted interest shall
          be paid to the person in whose name such bond (or any bond issued
          upon registration of transfer or exchange thereof) is registered
          on a subsequent record date established by notice given by mail
          by or on behalf of the Company to the holders of Series F Bonds
          not less than ten days preceding such subsequent record date. 
          The term "record date" shall mean, with respect to any semi-
          annual interest payment date for the Series F Bonds, the close of
          business on the 15th day of April or the 15th day of October, as
          the case may be, next preceding such interest payment date, or
          with respect to any payment of defaulted interest, the close of
          business on any subsequent record date established as provided
          above which shall be at least five business days prior to the
          payment date for such defaulted interest.

                    The principal of and the premium, if any, and interest
          on the Series F Bonds shall be payable in any coin or currency of
          the United States of America which at the time of payment is
          legal tender for the payment of public and private debts, at the
          principal office of the Trustee in the City of Boston,
          Massachusetts, or at the principal office of its successor as
          Trustee, or, at the option of the holder, (i) at the principal
          office of the Company's paying agent in the Borough of Manhattan,
          City of New York, New York, or (ii) at any other office or agency
          designated by the Company for the purpose.

                    Notwithstanding any provision to the contrary in the
          bonds of Series F or in the Indenture, Section 5.1 of the Bond
          Purchase Agreement dated as of June 1, 1993 pursuant to which the
          bonds of Series F were initially issued (hereinafter generally
          referred to as the Bond Purchase Agreement) shall govern payments
          with respect to the bonds of Series F to the bondholders referred
          to in said Section.  The Trustee hereby consents to the method of
          payment described in the aforesaid Section 5.1.  The Trustee also
          consents to the provisions of Section 6.3 of said Bond Purchase
          Agreement and agrees that if any lost, destroyed, stolen or
          mutilated bond of Series F was held by the original holder or an
          Institutional Investor, as defined in the Bond Purchase Agreement
          ("Institutional Investor"), of financial responsibility
          reasonably satisfactory to the Company, or any nominee for any
          such original holder or such Institutional Investor, (a) an
          agreement of indemnity reasonably satisfactory to the Company
          from such original holder or such Institutional Investor shall
          constitute indemnity satisfactory to the Trustee for purposes of
          Section 2.10 of the Indenture and (b) the Trustee will look only
          to the Company for reimbursement of its expenses incurred in
          connection with such replacement.

                    The bonds of Series F shall be exchangeable for a like
          aggregate principal amount of bonds of such series of other
          authorized denominations at the option of the holders and without
          charge, except that the Company, at its option, may require the
          payment of a sum sufficient to reimburse it for any stamp or
          other tax or governmental charge incident thereto.  The Trustee
          and the Trustee's authenticating agent are hereby appointed
          registrars of the bonds of Series F for the purpose of
          registering transfers and exchanges of bonds of Series F as
          herein provided.

                    SECTION 2.  Original Issue of the Series F Bonds.  At
          any time after the execution and delivery of this Supplemental
          Indenture, upon the application of the Company, the Trustee shall
          authenticate and deliver $25,000,000 in aggregate principal
          amount of bonds of Series F, upon delivery of the instruments
          referred to in Sections 5.01, 5.03 and 5.05 of the Original
          Indenture, as heretofore and hereby supplemented, and receipt by
          the Trustee of the bonds to be authenticated, duly executed by
          the Company.

                    SECTION 3.  Redemption of Series F Bonds.  The Series F
          Bonds shall be redeemable in whole or in part (in multiples of
          $1,000) by the operation of the sinking fund provided therefor in
          Section 4 of this Supplemental Indenture, or by operation of
          various provisions of the Original Indenture, as heretofore
          supplemented, at the time or times specified therein, or, at the
          option of the Company, at any time and from time to time prior to
          maturity, in each instance at the applicable redemption price and
          accrued interest to the date fixed for redemption on the
          principal amount of the bonds being redeemed.  The applicable
          redemption price shall be:

                         (a)  100% of the principal amount of the bonds
               being redeemed (constituting the "Special Redemption
               Price"), if the bonds are redeemed through the operation of
               the sinking fund, or by the use of Trust Moneys, or pursuant
               to Section 9.13 of the Original Indenture, as heretofore
               supplemented, and

                         (b)  otherwise, 100% of the Called Principal plus
               the Yield-Maintenance Amount, as those terms are defined in
               the form of Series F Bonds hereinbefore set forth.

                    On any redemption of bonds of Series F, the Trustee, in
          the name and on behalf of the Company, shall mail, by first class
          mail, postage prepaid, a notice of redemption to each registered
          holder of a bond to be redeemed (in whole or in part) at the last
          address of such holder appearing on the bond register; provided,
          however, that, in the case of any redemption of bonds of Series F
          for which the applicable redemption price has as a component a
          Yield-Maintenance Amount (as defined in the bonds of Series F),
          the Company, and not the Trustee, shall mail the notice of
          redemption as aforesaid, and the Trustee shall have no
          responsibility or liability in connection with any acts or
          omissions by the Company related to the notice of any such
          redemption.  Such notice shall be mailed not less than 30 days
          prior to the date fixed for redemption.  

                    The Company shall notify the Trustee at least 15 days
          (or such fewer number of days as may be satisfactory to the
          Trustee) before the date on which any notice of redemption of
          bonds of Series F (otherwise than through the operation of the
          sinking fund) is required to be given by the Trustee.  The
          Company shall be responsible for delivering statements
          calculating Yield-Maintenance Amounts and resulting redemption
          prices to bondholders as required by the form of bond of Series F
          hereinbefore set forth and shall cause a similar statement to be
          delivered to the Trustee no later than the second business day
          (or such later date as may be satisfactory to the Trustee) before
          the applicable date fixed for redemption.

                    Section 9.7 of the Bond Purchase Agreement is a
          bondholders' redemption agreement (within the meaning of
          Section 8.02 of the Indenture) among the holders of the bonds of
          Series F, satisfactory to and a copy of which is on file with the
          Trustee, that provides for the method that shall be followed by
          the Trustee in selecting bonds or parts of bonds for redemption
          in the event such redemption is a redemption of a part only of
          the bonds of Series F.  The bonds of Series F provide that, by
          the acceptance thereof, the holders thereof are deemed to have
          executed, and are bound by the terms of, the Bond Purchase
          Agreement.  Section 9.7 thereof provides that the principal
          amount of any partial redemption of the bonds of Series F shall
          be allocated, in units of $1,000 or integral multiples thereof,
          among the holders of the bonds of Series F at the time
          outstanding, in proportion, as nearly as practicable, to the
          respective unpaid principal amount of the bonds of Series F held
          thereby, with adjustments, to the extent practicable, to equalize
          for any prior redemption not made in exactly such proportion.

                    SECTION 4.  Sinking Fund for Series F Bonds.  The
          Company covenants that, as a sinking fund for the bonds of
          Series F, and so long as any of such bonds are outstanding, it
          will, subject to the provisions of the Bond Purchase Agreement,
          deposit with the Trustee cash in the amount of $1,667,000 at
          least one business day before May 1, 1994, and at least one
          business day before each May 1 thereafter through May 1, 2007
          (each such May 1 being hereinafter referred to as a "Sinking Fund
          Date"), such cash to be held subject to the provisions hereof.

                    The Trustee shall apply the amount of the cash so
          deposited with it by the Company hereunder to the redemption, in
          accordance with Article VIII of the Original Indenture, as
          heretofore supplemented, on the Sinking Fund Date before which
          such deposit is required to be made, of Series F Bonds in an
          aggregate principal amount equal to the amount of cash so
          deposited.  Each deposit of cash with the Trustee pursuant hereto
          shall, subject to the provisions of the Bond Purchase Agreement,
          be accompanied by a further deposit in an amount sufficient to
          pay the accrued interest on the Series F Bonds to be redeemed,
          and such further deposit shall be applied by the Trustee to the
          payment of such interest.

                    SECTION 5.  Yield-Maintenance Amount for Series F
          Bonds.  The Company further covenants that, so long as any of
          Series F Bonds are outstanding, upon any declaration pursuant to
          Section 10.01 of the Original Indenture that the principal and
          interest accrued on all the bonds then outstanding are due and
          payable immediately, the amounts then immediately due and payable
          with respect to the outstanding Series F Bonds shall consist of
          (i) the principal amount thereof, (ii) all interest accrued and
          unpaid thereon, and (iii) the Yield-Maintenance Amount (as
          hereinafter defined), if any, with respect to each such Series F
          Bond; provided, however, that such Yield-Maintenance Amount shall
          be due and payable upon such declaration only if the following
          conditions are satisfied:

                    (a)  Such declaration is based upon an event of default
          under any clause of said Section 10.01 other than clauses (f) and
          (g) thereof; and

                    (b)  The Trustee or the holders of at least 25% in
          principal amount of the bonds then outstanding under the
          Indenture, as the case may be, shall have given to the Company,
          at least ten (10) business days before such declaration, written
          notice stating its or their intention so to declare the bonds to
          be immediately due and payable and identifying one or more such
          events of default the occurrence of which, on or before the date
          of such notice, permits such declaration, and one or more of the
          events of default so identified shall be continuing at the time
          of such declaration; provided that if, on the date of said notice
          or prior to the date of the declaration made pursuant thereto,
          the Trustee or any other holders of at least 25% in principal
          amount of bonds then outstanding under the Indenture shall have
          declared the principal of and interest accrued on all the bonds
          then outstanding to be immediately due and payable, then,
          anything herein to the contrary notwithstanding, the Yield-
          Maintenance Amount, if any, on the bonds of Series F shall be
          immediately due and payable on the date of such declaration by
          the Trustee or such other holders.

                    For the purposes of this Section 5, the term "Yield-
          Maintenance Amount" and all related terms shall have the meanings
          ascribed thereto in the form of Series F Bond hereinbefore set
          forth, provided that the definitions therein of the related terms
          "Called Principal" and "Settlement Date" shall be revised to read
          as follows:

                         "Called Principal" shall mean, with respect to any
               bond of Series F, the principal of such bond that is to be
               redeemed or is declared immediately due and payable pursuant
               to Section 10.01 of the Indenture, as the context requires.

                         "Settlement Date" shall mean, with respect to the
               Called Principal of any bond of Series F, the date on which
               such Called Principal is to be redeemed or is declared to be
               immediately due and payable pursuant to Section 10.01 of the
               Indenture, as the context requires.

                    SECTION 6.  Retirement of Series F Bonds.  The Company
          shall not, and shall not permit any of its subsidiaries or
          affiliates to, redeem or otherwise retire in whole or in part
          prior to their stated final maturity (other than pursuant to
          Section 3 or 4 hereof or upon acceleration of such final maturity
          pursuant to Section 10.01 of the Original Indenture, as
          heretofore supplemented), or purchase or otherwise acquire,
          directly or indirectly, Series F Bonds held by any holder, unless
          the Company or such subsidiary or affiliate shall have offered to
          redeem or otherwise retire or purchase or otherwise acquire, as
          the case may be, the same proportion of the aggregate principal
          amount of the Series F Bonds held by each other holder of a
          Series F Bond at the time outstanding upon the same terms and
          conditions.  Any Series F Bonds so redeemed or otherwise retired
          or purchased or otherwise acquired by the Company or any of its
          subsidiaries or affiliates shall not be deemed to be outstanding
          for any purpose under the Indenture, as heretofore and hereby
          supplemented, subject to the terms of sub-clause (4) of the
          definition of the term "outstanding" in Section 1.01(ee) of the
          Original Indenture.

                    SECTION 7.  Pledged Contracts.  So long as any of the
          Series F Bonds are outstanding, the Company will comply with the
          provisions of subsections (a) and (b) of Section 6.13 of the
          Original Indenture, as heretofore supplemented, and, except with
          the consent of holders of 66-2/3% in principal amount of the
          Series F Bonds outstanding, will observe the prohibitions and
          limitations of subsection (c) of said Section 6.13.

                    SECTION 8.  The Trustee.  The Trustee shall be entitled
          to, may exercise and shall be protected by, where and to the full
          extent that the same are applicable, all the rights, powers,
          privileges, immunities and exemptions and shall be subject to the
          duties and liabilities of the Trustee, provided in the Original
          Indenture, as heretofore supplemented and confirmed and as herein
          supplemented and confirmed.  The remedies and provisions of the
          Original Indenture, as heretofore supplemented and confirmed and
          as herein supplemented and confirmed, applicable in case of any
          default by the Company thereunder, are hereby adopted and made
          applicable in case of any such default with respect to the
          properties included herein.  Without limitation of the generality
          of the foregoing, there are hereby conferred upon the Trustee the
          same powers of sale and other powers over the properties
          described herein as are by the Original Indenture, as heretofore
          supplemented, expressed to be conferred.

                    SECTION 9.  No Liability for Recitals.  The recitals
          contained herein and in the bonds (except the Trustee's
          authentication certificate) shall be taken as the statements of
          the Company and the Trustee assumes no responsibility for the
          correctness of the same.  The Trustee makes no representations as
          to the value of the mortgaged and pledged property or any part
          thereof, or as to the title of the Company thereto; or as to the
          validity or adequacy of the security afforded thereby and by the
          Indenture, or as to the validity of the Indenture or of the bonds
          or coupons issued thereunder.  The Trustee shall not be
          responsible for the effect, authorization, execution, delivery or
          recording of this Supplemental Indenture, except as expressly set
          forth in the Original Indenture, as heretofore supplemented.  The
          Trustee shall not be taken impliedly to waive by this
          Supplemental Indenture any right it would otherwise have.

                    SECTION 10.  The Original Indenture.  This Supplemental
          Indenture is expressly made supplemental to, and shall form a
          part of, the Original Indenture, as heretofore supplemented, and
          the conveyances hereby made are subject to all of the conditions,
          covenants and warranties in the Original Indenture, as heretofore
          supplemented, contained, and the use of terms and expressions
          herein is in accordance with the definitions and constructions
          contained in the Original Indenture, as heretofore supplemented. 
          This Supplemental Indenture shall become void when the Original
          Indenture, as heretofore supplemented, shall be void.

                    SECTION 11.  Trust Indenture Act to Control.  If any
          provision of this Supplemental Indenture limits, qualifies or
          conflicts with the duties imposed by any of Sections 310 to 317,
          inclusive, of the Trust Indenture Act of 1939, as amended by the
          Trust Indenture Reform Act of 1990, through operation of Section
          318(c), such imposed duties shall control.

                    SECTION 12.  Effect of Headings.  The headings of the
          different Sections of this Supplemental Indenture are inserted
          for convenience of reference, and are not to be taken to be any
          part of those provisions, or to control or affect the meaning,
          construction or effect of the same.

                    SECTION 13.  Counterparts.  This Supplemental Indenture
          is being simultaneously executed in several counterparts, all of
          which are identical, and all said counterparts are to be deemed
          to constitute but one and the same instrument.

                    IN WITNESS WHEREOF, Maine Yankee Atomic Power Company
          has caused this Supplemental Indenture to be executed on its
          behalf by its President or one of its Vice Presidents or its
          Treasurer and its corporate seal to be hereunto affixed and
          attested by its Secretary or an Assistant Secretary; and The
          First National Bank of Boston, as Trustee, has caused this
          Supplemental Indenture to be executed on its behalf and its
          corporate seal to be hereunto affixed by one of its Authorized
          Officers or Authorized Signatories; all as of the day and year
          first above written but actually on the date or dates set forth
          in the Acknowledgments hereto.

                                        MAINE YANKEE ATOMIC POWER COMPANY


                                        By   s/Michael E. Thomas           
                                               Treasurer

          [Corporate Seal]

          Attest:

           s/William M. Finn             
               Secretary


          Signed, sealed and delivered on
            behalf of Maine Yankee Atomic
            Power Company in the presence
            of:


           s/Judith Sargent                 



                                        THE FIRST NATIONAL BANK OF BOSTON,
                                                                  Trustee


                                        By  s/J. E. Mogavero               
                                           

          [Corporate Seal]

          Signed, sealed and delivered on
            behalf of The First National
            Bank of Boston in the presence
            of:

           s/E. J. Donaghey              


          

          STATE OF MAINE      )
                              ) ss.:
          COUNTY OF KENNEBEC  )

                    On this  2nd  day of June, 1993, before me appeared   
          Michael E. Thomas, the Treasurer of Maine Yankee Atomic Power
          Company, to me personally known, who executed the foregoing
          instrument on behalf of said corporation and acknowledged the
          same to be his free act and deed in said capacity and the free
          act and deed of Maine Yankee Atomic Power Company.

                    WITNESS my hand and official seal the day and year
          first above written.

                                      s/Geraldine Downer Scott             
                                                  Notary Public
                                        Geraldine Downer Scott
                                        Notary Public, Maine
                                        My Commission Expires May 1, 1995
                                     

                                                 (Notarial Seal)




          COMMONWEALTH OF MASSACHUSETTS )
                                        ) ss.:
          COUNTY OF SUFFOLK             )

                    On this  1st  day of June, 1993, before me appeared     
            J. E. Mogavero  , an   Authorized Officer  of The First
          National Bank of Boston, to me personally known, who executed the
          foregoing instrument on behalf of said corporation and
          acknowledged the same to be such person's free act and deed in
          said capacity and the free act and deed of The First National
          Bank of Boston.

                    WITNESS my hand and official seal the day and year
          first above written.



                                     s/Shawn Patrick George                
                                                  Notary Public
                                        Shawn Patrick George
                                        Notary Public
                                        My Commission Expires
                                        September 2, 1999

                                                 (Notarial Seal)