1
                                                                     Exhibit 4.1

                                 AMENDMENT NO. 2
                           TO POWER PURCHASE AGREEMENT

      This Amendment No. 2 to Power Purchase Agreement  ("Second  Amendment") is
entered into as of the 26th day of June , 1998 by and between  PENOBSCOT  ENERGY
RECOVERY COMPANY,  LIMITED PARTNERSHIP,  a Maine limited partnership ("Seller"),
and BANGOR HYDRO-ELECTRIC COMPANY, a Maine corporation ("Buyer").

                              W I T N E S S E T H:

      WHEREAS,  Seller and Buyer are parties to a Power Purchase Agreement dated
June 21, 1984 and amended by  Amendment  No. 1 dated March 24, 1986 (as amended,
the  "Agreement") for the sale by Seller and the purchase by Buyer of energy and
capacity  from  Seller's   Orrington,   Maine   waste-to-energy   facility  (the
"Facility"); and

      WHEREAS,   Seller  has  entered  into  certain  long-term  waste  disposal
agreements with numerous Maine municipalities, pursuant to a standard form First
Amended  and  Restated  Waste  Disposal  Agreement  dated as of April 1, 1991 or
shortly  thereafter (the "First Waste Disposal  Agreement") and intends to enter
into a standard  form Second  Amended,  Restated  and  Extended  Waste  Disposal
Agreement  (the  "Second  Waste  Disposal  Agreement")  with  many  of the  same
municipalities as of the Closing (as hereinafter defined); and

      WHEREAS,  those  municipalities  which  are  parties  to the  First  Waste
Disposal Agreement are known as the "Charter Municipalities"; and

      WHEREAS,  those  municipalities  which become  parties to the Second Waste
Disposal Agreement are known as "Amending Charter Municipalities;" and

      WHEREAS,  the Amending Charter  Municipalities will be directly benefitted
by this Agreement,  because it is expected that the continuing sale of energy by
Seller to Buyer will enable Seller to economically receive and process municipal
solid  waste under the Second  Waste  Disposal  Agreement,  which is expected to
substantially  assist the Amending  Charter  Municipalities  in the discharge of
their  obligation  to provide  for the  disposition  of  municipal  solid  waste
discarded by their residents and businesses; and


                                       1
   2

      WHEREAS, in accordance with 35-A M.R.S.A.  ss.3156, Buyer has conclusively
determined that (i) this Second  Amendment  provides  near-term  benefits to its
rate payers that will be reflected in rates paid by the Buyer's  customers;  and
(ii) as a result of this Second Amendment, potential future adverse rate impacts
are not likely to be  disproportionate to near-term gains; and (iii) this Second
Amendment  is  consistent  with 35-A  M.R.S.A.  ss.3191;  and (iv)  this  Second
Amendment will not adversely  impact the  availability of a diverse and reliable
mix of electric energy resources and will not significantly reduce the long-term
electric  energy or  capacity  resources  available  to Buyer and needed to meet
future electric demand; and

      WHEREAS, consistent with 35-A M.R.S.A.  ss.3208(4), Buyer has conclusively
determined that this Second Amendment will reduce the Buyer's potential stranded
costs; and

      WHEREAS, at the request of Buyer, Seller is entering into a loan agreement
(the "Bond Financing Agreement") with the Finance Authority of Maine ("FAME") to
provide a loan to Seller  pursuant to FAME's  electric rate  stabilization  loan
program,  as defined in 10 M.R.S.A.  ss.963-A  (7-A), by issuing bonds (the "New
Bonds") to  refinance  and replace  the  existing  loan  provided to Seller from
certain  bonds issued by the Town of Orrington,  Maine (the "Old Bonds"),  which
Old Bonds financed a portion of the construction of the Facility; and

      WHEREAS,  this Amendment is being executed and delivered  contingent  upon
the closing of the  refinancing  referred  to in the  preceding  paragraph  (the
"Closing"); and

      WHEREAS, delivery of the New Bonds shall be conclusive evidence that the
Closing has occurred; and

      WHEREAS,  Seller,  Municipal Review Committee,  Inc. (the "MRC") and Buyer
have approved the Bond Financing  Agreement and the Trust  Indenture (the "Trust
Indenture")  to be entered  into as of the  Closing  between  FAME and The Chase
Manhattan Bank, as the trustee for the New Bonds (the "Bond Trustee"),  pursuant
to which the Bond Trustee will receive specified  payments from Seller and Buyer
at Closing to fund certain  reserves held in trust by the Bond Trustee under the
Trust Indenture; and

      WHEREAS,  all Charter  Municipalities  are members of the MRC which is the
designated  agent  for  the  Charter  Municipalities  and the  Amending  Charter
Municipalities; and


                                       2
   3

      WHEREAS,   Seller  and  Buyer   understand   that  the  Amending   Charter
Municipalities  will  receive  certain  benefits  as a  result  of  this  Second
Amendment and related transactions,  and intend that the MRC shall be an express
third  party  beneficiary  hereunder  for the  benefit of the  Amending  Charter
Municipalities to the extent provided herein; and

      WHEREAS,  Buyer intends to issue  warrants to the MRC or its designees for
the benefit of Amending Charter Municipalities at the Closing; and

      WHEREAS, the MRC and Buyer are separately entering into an agreement as of
the  Closing  regarding  certain  operating  reports  about the  Facility  to be
prepared  periodically  by the MRC for which  Buyer  shall  pay  Forty  Thousand
Dollars  ($40,000.00)  annually (subject to annual adjustment in accordance with
changes in the  "CPI-U,"  so-called,  published by the United  States  Bureau of
Labor  Statistics),  payable Ten  Thousand  Dollars  ($10,000.00)  quarterly  in
advance;

      NOW THEREFORE,  in  consideration of the mutual covenants and promises set
forth  herein,  and  the  consent  of  the  MRC  and  other  good  and  valuable
consideration,  the receipt  and  sufficiency  of which is hereby  acknowledged,
Seller and Buyer agree as follows:

      1.    It is the express intent of Seller and Buyer that the MRC possess an
            enforceable benefit for the Amending Charter Municipalities as a
            third party beneficiary of the Agreement. As a third party
            beneficiary, it is intended that the MRC shall have standing in any
            suit, bankruptcy, reorganization, arbitration, mediation or dispute
            resolution proceeding arising out of the Agreement to enforce any
            rights granted to the Amending Charter Municipalities or the MRC
            hereunder, or to seek damages from the breach of any obligations
            owed to the Amending Charter Municipalities and the MRC hereunder.

      2.    The following  provisions  of the Agreement  shall not be materially
            amended,  supplemented  or  modified  without  the  express  written
            consent of the MRC, which consent shall not be unreasonably withheld
            or delayed:

      Article II:    Term
      Article III:   Sale of Power
      Article IV:    Billing and Payment
      Article IX:    Deliveries
      Article XI:    Continuity of Service
      Article XIII:  Breach
      Article XIV:   Assignment


                                       3
   4

      Article XV:    Indemnity
      Article XVI:   Liability, Dedication
      Article XVII:  Force Majeure

      Article XIX:   Representations and Warranties of the Parties
      Article XXI:   Waiver
      Article XXIII: Choice of Law
      The First and Second Amendments to the Agreement

      3.    At the Closing Buyer will (a) deposit with the Bond Trustee for the
            benefit of Seller Six Million Dollars ($6,000,000.00) for credit to
            the Capital Reserve Fund established under the Trust Indenture and
            (b) a one-time payment of $151,393, which is an amount equal to
            interest at the rate of eight percent (8%) per annum on One Million
            Dollars ($1,000,000.00) over sixteen quarter-year periods,
            discounted at the same interest rate (together, the "Closing
            Payment"), for deposit under the terms of the Trust Indenture. Buyer
            will pay to the Bond Trustee for the benefit of Seller and the MRC,
            as agent for the Amending Charter Municipalities additional cash
            payments in the aggregate amount of Four Million Dollars
            ($4,000,000), for deposit under the terms of the Trust Indenture, in
            quarterly payments of Two Hundred Fifty Thousand Dollars
            ($250,000.00) due on the first day of each quarter for each quarter
            or part thereof (January, April, July, October) which occurs after
            the Closing, commencing October 1, 1998, until sixteen such
            quarterly payments have been made (the "Installment Payments," and
            together with the Closing Payment, the "Bangor Hydro Payments," and
            each date of such payment, the "Payment Date"). All Bangor Hydro
            Payments shall be made to the Bond Trustee but if a Bond Trustee is
            not serving in such capacity on a particular Payment Date then the
            Bangor Hydro Payment shall be made as Seller shall direct Buyer in
            writing. The obligation of Buyer to make each of the Bangor Hydro
            Payments shall be absolute and unconditional, and Buyer shall not be
            entitled to any abatement, diminution, set off, abrogation, waiver
            or modification thereof nor to any termination of the Agreement by
            any reason whatsoever except as expressly provided herein,
            regardless of any rights of set-off, recoupment or counterclaim that
            Buyer might otherwise have against Seller or any other party or
            parties and regardless of any contingency, act of God, event or
            cause whatsoever.

      4.    Buyer and  Seller  each  agree to pay by wire  transfer  of same day
            funds on the  Closing  Date or as soon  thereafter  as  practicable,
            one-half  (1/2)  of the  third  party  costs  of  restructuring  the
            financing described above including but not limited to costs related
            to: (a) extension and  termination of the letter of credit  securing
            the Old Bonds, (b) retirement of the Old Bonds, (c)


                                       4
   5

            issuance of the New Bonds and loans related  thereto,  (d) obtaining
            FAME approval; and all of certain costs of other entities including,
            but not limited to,  reasonable  expenses  incurred by the MRC,  the
            Town of Orrington, bond counsel, FAME, the existing letter of credit
            banks,  and the Bond Trustee,  and their  respective  counsel,  with
            credit for such portion thereof that may have been advanced by Buyer
            or Seller, respectively, prior to the Closing.

      5.    Subject to the satisfaction of the requirements contained in
            Paragraph 6 below, Seller shall pay to Buyer one-third (1/3) of any
            Distributable Cash (as such term is defined in the Second Waste
            Disposal Agreement), which is available for distribution in
            accordance with the Trust Agreement, but only to the extent
            permitted under the Bond Financing Agreement (each such payment a
            "Bangor Hydro Distribution"), as more particularly described in the
            Surplus Cash Agreement of even date herewith among Buyer, Seller,
            and the MRC.

      6.    Seller's obligation to make a Bangor Hydro Distribution to Buyer is
            contingent on Buyer making each Installment Payment as and when due
            and performing each of its other obligations set forth in the
            Agreement, as amended hereby. In the event of a payment default
            hereunder by Buyer, Buyer shall immediately rebate to the Bond
            Trustee (or if none, to Seller) all Bangor Hydro Distributions
            previously received by Buyer in an amount equal to the sum of the
            Bangor Hydro Payments (together with any other payments due
            hereunder) which have not been paid when due, which rebate amount
            (net of costs of collection) shall be distributed as directed in
            writing by Seller.

      7.    In the event that Buyer's obligation to make payments under the
            Agreement is avoided, or otherwise reduced in amount, or delayed, or
            impaired in a bankruptcy, reorganization, or similar proceeding,
            Seller's obligation to make any further Bangor Hydro Distributions
            shall cease, and Seller and the MRC shall have valid and enforceable
            claims against Buyer in the aggregate amount of all Bangor Hydro
            Distributions previously paid to Buyer, net of any reserves funded
            by Bangor Hydro Payments and held by the Bond Trustee under the
            Trust Indenture, in addition to any other claims for damages or
            other claims Seller and the MRC may possess.


                                       5
   6

      8.    Article V of the Agreement is amended as follows:

      To Seller:  Penobscot Energy Recovery Company, Limited Partnership
                  P.O. Box 96
                  Industrial Way
                  Orrington, ME  04475
                  Attention: Plant Manager

      With a copy (which shall not constitute notice) to:
                  Gordon F. Grimes, Esq.
                  Bernstein, Shur, Sawyer & Nelson
                  100 Middle Street
                  P.O. Box 9729
                  Portland, ME 04104-5029

      To Buyer:   President
                  Bangor Hydro-Electric Company
                  33 State Street
                  P.O. Box 932
                  Bangor, ME  04402-0932

      To Municipal Review Committee, Inc.:
                  Municipal Review Committee, Inc.
                  Eastern Maine Development Corporation
                  One Cumberland Place
                  Bangor, ME  04401

      With a copy (which shall not constitute notice) to:
                  Thomas M. Brown, Esq.
                     Eaton, Peabody, Bradford & Veague, P.A.
                  Fleet Center - Exchange Street
                  P.O. Box 1210
                  Bangor, ME  04402-1210

Monthly billing statements to Buyer shall be sent to:
                  Assistant Treasurer
                  Bangor Hydro-Electric Company
                  33 State Street
                  P.O. Box 932
                  Bangor, ME  04402-0932

9.    Article IX of the Agreement is amended by adding the following at the end
      of the last sentence of the first paragraph:

            "...until  such time as retail access is permitted  pursuant to 35-A
            M.R.S.A.  ss.3202 or any successor  statute.  Thereafter  Seller may
            (without  waiving any right to continue  buying from Buyer from time
            to time  thereafter)  purchase  such power as  permitted by statute,
            which shall be delivered by Buyer if requested by Seller."


                                       6
   7

      10. Article XIII(A) of the Agreement is amended by adding the following at
the end of the first sentence:

            "...and in addition  Buyer shall pay all Bangor  Hydro  Payments set
            forth in paragraphs 6 and 7 of the Second Amendment hereof."

      11. Article XIV of the Agreement is amended by adding the following  words
after the words "that the Trustee to which this  Agreement  is  assigned" in the
second sentence thereof:

            "...,  upon taking  possession of the Facility after  foreclosure of
            its liens on and security interests therein,...

      12. Article XV of the Agreement is amended by inserting the following
immediately after the first sentence thereof:

            "Notwithstanding the above, no limitation appearing in the preceding
            sentence will be construed to limit payment of the amounts described
            in paragraphs 6 and 7 of the Second Amendment hereof."

13. Article XVI is amended by adding the following to Section A:

            "...except obligations to the MRC as provided for herein."

14. Article XXIV of the Agreement is amended by adding the following:

            "...other than such terms and conditions referred to in documents
            referred to in the Second Amendment."

Buyer  acknowledges that any default under the Agreement  referenced in the 15th
WHEREAS  clause hereof shall not be a default under this Agreement or in any way
excuse  performance by Buyer hereunder or give rise to any rights of offset with
respect thereto. In all other respects, the Agreement shall remain in full force
and  effect in  accordance  with the terms  thereof,  and  Seller and Buyer each
hereby reaffirms its respective obligations thereunder.


                                       7
   8

IN WITNESS  WHEREOF,  Seller and Buyer have  caused this  Amendment  No. 2 to be
executed as of the date first written above.

WITNESS:                            Penobscot Energy Recovery Company, Limited
                                   Partnership

                                    By: PERC Management Company Limited
                                    Partnership, its General Partner

                                    By: PERC, Inc. its General Partner


/s/ Robert E. Wetzel                By: /s/ Martin J. Sergi
- -----------------------             -----------------------
Name:  Robert E. Wetzel                   Martin J. Sergi
                                          Its President

                                    By: Energy National, Inc., its General
                                        Partner

/s/ David Lloyd                     By: /s/ Michael J. Young
- ----------------------              ------------------------
Name: David Lloyd                         Michael J. Young
                                          Its Secretary

                                          Bangor Hydro-Electric Company

/s/ Andrew Landry                   By: /s/ Carroll R. Lee
- ---------------------               ------------------------
Name: Andrew Landry                       Carroll R. Lee
                                          Its Senior Vice President and Chief
                                          Operating Officer


                                       8