TRANSITION PROPERTY PURCHASE AND SALE AGREEMENT

Exhibit 10.1.1.

EXECUTION COPY

TRANSITION PROPERTY PURCHASE AND SALE AGREEMENT

between

BEC FUNDING II, LLC

Note Issuer

and

BOSTON EDISON COMPANY

Seller

Dated as of March 1, 2005

TABLE OF CONTENTS

-1-

This TRANSITION PROPERTY PURCHASE AND SALE AGREEMENT, dated as of March 1, 2005 is between BEC Funding II, LLC, a Delaware limited liability company (the “ Note Issuer ”), and Boston Edison Company, a Massachusetts corporation (together with its successors in interest to the extent permitted hereunder, the “ Seller ”).

RECITALS

WHEREAS, the Note Issuer desires to purchase the Transition Property (as defined herein) created pursuant to the Statute and the Financing Order (each as defined herein); and

WHEREAS, the Seller is willing to sell the Transition Property to the Note Issuer.

NOW, THEREFORE, in consideration of the premises and the mutual covenants herein contained, the parties hereto agree as follows:

ARTICLE I. DEFINITIONS

Section 1.01. Definitions . Whenever used in this Agreement, the following words and phrases shall have the following meanings:

“ Administration Agreement ” means the Administration Agreement dated as of March 1, 2005 between Boston Edison Company, as Administrator, and the Note Issuer, as amended and supplemented from time to time.

“ Agencies ” means, collectively, the Massachusetts Health and Educational Facilities Authority and the Massachusetts Development Finance Agency.

“ Agreement ” means this Transition Property Purchase and Sale Agreement, as amended and supplemented from time to time.

“ Back-Up Security Interest ” has the meaning specified in Section 2.01.

“ Basic Documents ” means, collectively, this Agreement, the Note Indenture, the Declaration of Trust, the Certificate Indenture, the Servicing Agreement, the Administration Agreement, the Note Purchase Agreement, the Underwriting Agreement, the Fee and Indemnity Agreement and the Cross Indemnity Agreement.

“ Business Day ” means any day other than a Saturday, a Sunday or a day on which banking institutions or trust companies in New York, New York, Boston, Massachusetts or Wilmington, Delaware are authorized or obligated by law, regulation or executive order to remain closed.

“ Certificate Indenture ” means the Certificate Indenture dated as of March 1, 2005, between the Certificate Issuer and the Certificate Trustee, as amended and supplemented from time to time.

“ Certificate Trustee ” means the Person acting as trustee under the Certificate Indenture.

-2-

“ Certificateholders ” has the meaning specified in Section 1.01(a) of the Certificate Indenture.

“ Certificates ” means the Massachusetts RRB Special Purpose Trust 2005-1 Rate Reduction Certificates issued under the Certificate Indenture.

“ Closing Date ” means March 1, 2005.

“ Collection Account ” has the meaning specified in Section 8.02(a) of the Note Indenture.

“ Corporate Trust Office ” has the meaning specified in Section 1.01(a) of the Note Indenture.

“ Cross Indemnity Agreement ” means the Cross Indemnity Agreement dated as of March 1, 2005 between the Note Issuer and CEC Funding, LLC, as amended and supplemented from time to time.

“ Customers ” means all classes of retail users of the Seller’s distribution system within its geographic service territory as in effect on July 1, 1997.

“ Date of Breach ” means, with respect to the repurchase obligation specified in Section 5.01(b), the date of breach of a representation or warranty that triggers such repurchase obligation.

“ Declaration of Trust ” means the Declaration of Trust dated as of January 26, 2005, among the Agencies and the Delaware Trustee, as amended and supplemented from time to time.

“ Delaware Trustee ” means the Person acting as trustee under the Declaration of Trust.

“ DTE ” means the Massachusetts Department of Telecommunications and Energy and any successor thereto.

“ DTE Regulations ” has the meaning specified in Section 1.01 of the Servicing Agreement.

“ Fee and Indemnity Agreement ” means the fee and indemnity agreement dated as of March 1, 2005 among the Note Issuer, the Delaware Trustee, the Certificate Trustee, the Trust and the Agencies.

“ Financing Order ” means the order of the DTE in Docket No. D.T.E. 04-70, issued on January 21, 2005.

“ Grant ” means mortgage, pledge, collaterally assign and grant a lien upon and a security interest in. A Grant of any agreement or instrument shall include all rights, powers and options (but none of the obligations) of the Granting Person thereunder, the immediate and continuing

-3-

right to claim for, collect, receive and give receipts for payments in respect of and all other monies payable thereunder, to give and receive notices and other communications, to make waivers or other agreements, to exercise all rights and options, to bring proceedings in the name of the Granting Person or otherwise, and generally to do and receive anything that the Granting Person is or may be entitled to do or receive thereunder with respect thereto.

“ Indemnified Person ” has the meaning specified in Section 5.01(h).

“ Issuance Advice Letter ” means the initial Issuance Advice Letter, dated February 18, 2005, filed with the DTE by the Seller pursuant to the Financing Order.

“ Lien ” means a security interest, lien, charge, pledge or encumbrance of any kind.

“ Losses ” has the meaning specified in Section 5.01(e).

“ Moody’s ” means Moody’s Investors Service, Inc. or its successor.

“ Note Indenture ” means the Note Indenture dated as of March 1, 2005, between the Note Issuer and the Note Trustee, as amended and supplemented from time to time.

“ Note Issuer ” has the meaning set forth in the preamble of this Agreement.

“ Note Purchase Agreement ” means the Note Purchase Agreement dated as of March 1, 2005 between the Note Issuer and the Trust, as amended and supplemented from time to time.

“ Note Register ” has the meaning specified in Section 2.05 of the Note Indenture.

“ Note Trustee ” means the Person acting as trustee under the Note Indenture.

“ Noteholder ” or “ Holder ” means the Person in whose name a Note is registered on the Note Register.

“ Notes ” means the BEC Funding II, LLC Notes issued under the Note Indenture.

“ Officer’s Certificate ” means a certificate signed by the chairman of the board, the chief executive officer, the president, the chief financial officer, any vice president, the treasurer, any assistant treasurer, the clerk, any assistant clerk, the controller or the director of corporate finance and cash management of the Seller.

“ Operating Expense ” has the meaning specified in Section 1.01(a) of the Note Indenture.

“ Opinion of Counsel ” means one or more written opinions of counsel who may be an employee of or counsel to the party providing such opinion of counsel, which counsel shall be reasonably acceptable to the party receiving such opinion of counsel.

-4-

“ Outstanding Amount ” has the meaning specified in Section 1.01(a) of the Note Indenture.

“ Overcollateralization Subaccount ” has the meaning specified in Section 8.02(a) of the Note Indenture.

“ Person ” means any individual, corporation, limited liability company, estate, partnership, joint venture, association, joint stock company, trust (including any beneficiary thereof), unincorporated organization or government or any agency or political subdivision thereof.

“ Rating Agencies ” means, collectively, S&P and Moody’s.

“ Repurchase Date ” means the date that is five Business Days after the date that is (i) if the terms of Section 5.01(b)(i)(A) and Section 5.01(b)(i)(B)(2) are applicable, two Business Days after the Date of Breach if the Seller fails to make the deposit required by Section 5.01(b)(i)(B)(2) or 90 days after the Date of Breach if the Seller makes the deposit required by Section 5.01(b)(i)(B)(2); (ii) if the terms of Section 5.01(b)(ii) are applicable, 90 days after the Date of Breach; and (iii) if the terms of Section 5.01(b)(i)(A) and Section 5.01(b)(i)(B)(1) are applicable, 90 days after the Date of Breach.

“ Required Overcollateralization Level ” has the meaning specified in Section 1.01(a) of the Note Indenture.

“ Repurchase Price ” has the meaning specified in Section 5.01(b)(i).

“ RTC Charge ” means the portion (which may become all) of the Seller’s Transition Charge designated pursuant to the Financing Order as the RTC Charge, as the same may be adjusted from time to time as provided in the Financing Order, and may in the future include a pro rata component of any exit charge collected pursuant to Section 1G(g) of Chapter 164 of the Massachusetts General Laws.

“ RTC Charge Collections ” has the meaning specified in Section 1.01 of the Servicing Agreement.

“ Seller ” has the meaning set forth in the preamble of this Agreement.

“ Servicer Default ” means an event specified in Section 7.01 of the Servicing Agreement.

“ Servicing Agreement ” means the Transition Property Servicing Agreement dated as of March 1, 2005 between Boston Edison Company, as Servicer, and the Note Issuer, as amended and supplemented from time to time.

“ S&P ” means Standard & Poor’s Ratings Services, a division of The McGraw Hill Companies, Inc. or its successor.

-5-

“ Statute ” means Chapter 164 of the Massachusetts Acts of 1997, entitled An Act Relative to Restructuring the Electric Utility Industry in the Commonwealth, Regulating the Provision of Electricity and Other Services, and Promoting Enhanced Consumer Protections Therein.

“ Transition Charge ” means the “access charge” as defined in Boston Edison Company’s Restructuring Settlement Agreement, D.P.U. Docket Nos. 96-100 and 96-23 and subsequent filings with the DTE pursuant thereto.

“ Transition Property ” means the transition property that exists under paragraph 6 of the Financing Order.

“ Trust ” or “ Certificate Issuer ” means Massachusetts RRB Special Purpose Trust 2005-1, a Delaware statutory trust.

“ UCC ” means, unless the context otherwise requires, the Uniform Commercial Code, as in effect in the relevant jurisdiction, as amended from time to time.

“ Underwriting Agreement ” means the Underwriting Agreement dated as of February 15, 2005 among Boston Edison Company, the Note Issuer, Commonwealth Electric Company, CEC Funding, LLC, and the underwriters named therein.

Section 1.02. Other Definitional Provisions .

(a) All terms defined in this Agreement shall have the defined meanings when used in any certificate or other document made or delivered pursuant hereto unless otherwise defined therein.

(b) The words “hereof,” “herein,” “hereunder” and words of similar import, when used in this Agreement, shall refer to this Agreement as a whole and not to any particular provision of this Agreement; Section, Schedule and Exhibit references contained in this Agreement are references to Sections, Schedules and Exhibits in or to this Agreement unless otherwise specified; and the term “including” shall mean “including without limitation”.

(c) The definitions contained in this Agreement are applicable to the singular as well as the plural forms of such terms.

ARTICLE II. CONVEYANCE OF TRANSITION PROPERTY

Section 2.01. Conveyance of Transition Property . In consideration of the Note Issuer’s delivery to or upon the order of the Seller of $265,467,619, the Seller does hereby irrevocably sell, transfer, assign, set over and otherwise convey to the Note Issuer, WITHOUT RECOURSE OR WARRANTY, except as specifically set forth herein, all right, title and interest of the Seller in and to the Transition Property (such sale, transfer, assignment, setting over and conveyance of the Transition Property includes, to the fullest extent permitted by the Statute, the assignment of all revenues, collections, claims, payments, money or proceeds of or arising from the RTC Charge pursuant to the Financing Order) and copies of all books and records related thereto. Such sale, transfer, assignment, setting over and conveyance is hereby expressly stated to be a

-6-

sale and, pursuant to Section 1H(f)(1) of Chapter 164 of the Massachusetts General Laws, shall be treated as an absolute transfer of all of the Seller’s right, title and interest in (as in a true sale), and not as a pledge or other financing of, the Transition Property. If such sale, transfer, assignment, setting over and conveyance is held by any court of competent jurisdiction not to be a true sale as provided in Section 1H(f)(1) of Chapter 164 of the Massachusetts General Laws, then such sale, transfer, assignment, setting over and conveyance shall be treated as the creation of a security interest in the Transition Property and, without prejudice to its position that it has absolutely transferred all of its rights in the Transition Property to the Note Issuer, the Seller hereby Grants to the Note Issuer a security interest in the Transition Property (including, to the fullest extent permitted by the Statute, the assignment of all revenues, collections, claims, payments, money or proceeds of or arising from the RTC Charge pursuant to the Financing Order) to secure a payment obligation incurred by the Seller in respect of the amount paid by the Note Issuer to the Seller pursuant to this Agreement (the “Back-Up Security Interest”). Such sale, transfer, assignment, setting over and conveyance of the Transition Property includes the right to use the Seller’s computer software system to access and create copies of all books and records related to the Transition Property.

ARTICLE III. REPRESENTATIONS AND WARRANTIES OF SELLER

Subject to Section 3.09 hereof, the Seller makes the following representations and warranties, as of the Closing Date, on which the Note Issuer has relied in acquiring the Transition Property.

Section 3.01. Organization and Good Standing . The Seller is duly organized and validly existing as a corporation in good standing under the laws of the Commonwealth of Massachusetts, with the requisite corporate power and authority to own its properties as such properties are currently owned and to conduct its business as such business is now conducted by it, and has the requisite corporate power and authority to own the Transition Property.

Section 3.02. Due Qualification . The Seller is duly qualified to do business as a foreign corporation in good standing, and has obtained all necessary licenses and approvals, in all jurisdictions in which the ownership or lease of property or the conduct of its business shall require such qualifications, licenses or approvals (except where the failure to so qualify or obtain such licenses and approvals would not be reasonably likely to have a material adverse effect on the Seller’s business, operations, assets, revenues or properties).

Section 3.03. Power and Authority . The Seller has the requisite corporate power and authority to execute and deliver this Agreement and to carry out its terms; and the execution, delivery and performance of this Agreement have been duly authorized by all necessary corporate action on the part of the Seller.

Section 3.04. Binding Obligation . This Agreement constitutes a legal, valid and binding obligation of the Seller enforceable against it in accordance with its terms, subject to applicable insolvency, reorganization, moratorium, fraudulent transfer and other laws relating to or affecting creditors’ or secured parties’ rights generally from time to time in effect and to general

-7-

principles of equity (including concepts of materiality, reasonableness, good faith and fair dealing), regardless of whether considered in a proceeding in equity or at law.

Section 3.05. No Violation . The consummation of the transactions contemplated by this Agreement and the fulfillment of the terms hereof do not: (i) conflict with or result in any breach of any of the terms and provisions of, nor constitute (with or without notice or lapse of time) a default under, the articles of organization or by-laws of the Seller, or any material indenture, agreement or other instrument to which the Seller is a party or by which it is bound; (ii) result in the creation or imposition of any Lien upon any of the Seller’s properties pursuant to the terms of any such indenture, agreement or other instrument (other than any Lien that may be Granted under the Basic Documents or any Lien created pursuant to Section 1H(e) of Chapter 164 of the Massachusetts General Laws); or (iii) violate any existing law or any existing order, rule or regulation applicable to the Seller of any court or of any federal or state regulatory body, administrative agency or other governmental instrumentality having jurisdiction over the Seller or its properties.

Section 3.06. No Proceedings . There are no proceedings pending and, to the Seller’s knowledge, there are no proceedings threatened and no investigations pending or threatened, before any court, federal or state regulatory body, administrative agency or other governmental instrumentality having jurisdiction over the Seller or its properties involving or relating to the Seller or the Note Issuer or, to the Seller’s knowledge, any other Person: (i) asserting the invalidity of this Agreement, any of the other Basic Documents, the Notes, the Certificates, the Statute or the Financing Order, (ii) seeking to prevent the issuance of the Notes or the Certificates or the consummation of any of the transactions contemplated by this Agreement or any of the other Basic Documents, (iii) seeking any determination or ruling that might materially and adversely affect the performance by the Seller of its obligations under, or the validity or enforceability of, this Agreement, any of the other Basic Documents, the Notes or the Certificates, or the validity of the Statute or the Financing Order or (iv) seeking to adversely affect the federal or state income tax classification of the Notes or the Certificates as debt.

Section 3.07. Approvals . No approval, authorization, consent, order or other action of, or filing with, any court, federal or state regulatory body, administrative agency or other governmental instrumentality is required in connection with the execution and delivery by the Seller of this Agreement, the performance by the Seller of the transactions contemplated hereby or the fulfillment by the Seller of the terms hereof, except those that have been obtained or made and those that the Seller, in its capacity as Servicer under the Servicing Agreement, is required to make in the future pursuant to the Servicing Agreement.

Section 3.08. The Transition Property .

(a) Title . It is the intention of the parties hereto that the transfer and assignment herein contemplated constitute a sale of the Transition Property from the Seller to the Note Issuer and that no interest in, or title to, the Transition Property shall be part of the Seller’s estate in the event of the filing of a bankruptcy petition by or against the Seller under any bankruptcy law. No portion of the Transition Property has been sold, transferred, assigned or pledged by the Seller to any Person other than the Note Issuer. On the Closing Date, immediately upon the sale hereunder, the Seller has transferred, sold and conveyed the Transition Property to the Note

-8-

Issuer, free and clear of all Liens, except for any Lien created pursuant to Section 1H(e) of Chapter 164 of the Massachusetts General Laws and any Lien that may be Granted under the Basic Documents, and pursuant to Section 1H(f)(1) of Chapter 164 of the Massachusetts General Laws such transfer shall be treated as an absolute transfer of all of the Seller’s right, title and interest (as in a true sale), and not as a pledge or other financing of, the Transition Property.

(b) Transfer Filings . On the Closing Date, immediately upon the sale hereunder, the Transition Property has been validly transferred and sold to the Note Issuer, the Note Issuer shall own all such Transition Property free and clear of all Liens (except for any Lien created pursuant to Section 1H(e) of Chapter 164 of the Massachusetts General Laws and any Lien that may be Granted under the Basic Documents) and all filings to be made by the Seller (including filings with the DTE under the Statute) necessary in any jurisdiction to give the Note Issuer a valid, perfected ownership interest (subject to any Lien created pursuant to Section 1H(e) of Chapter 164 of the Massachusetts General Laws and any Lien that may be Granted under the Basic Documents) in, and for the Grant by the Note Issuer to the Note Trustee of a valid, first priority perfected security interest (except for any Lien created pursuant to Section 1H(e) of Chapter 164 of the Massachusetts General Laws and any Lien that may be Granted under the Basic Documents) in, the Transition Property have been made. No further action is required to maintain such ownership interest or the Note Trustee’s perfected security interest (in each case, subject to any Lien created pursuant to Section 1H(e) of Chapter 164 of the Massachusetts General Laws and any Lien that may be Granted under the Basic Documents). Filings have also been made to the extent required in any jurisdiction to perfect the Back-Up Security Interest Granted by the Seller to the Note Issuer (subject to any Lien created pursuant to Section 1H(e) of Chapter 164 of the Massachusetts General Laws and any Lien that may be Granted under the Basic Documents).

(c) Financing Order and Issuance Advice Letter; Other Approvals . On the Closing Date, under the laws of The Commonwealth of Massachusetts and the United States in effect on the Closing Date, (i) the Financing Order pursuant to which the Transition Property has been created is in full force and effect; (ii) the Certificateholders are entitled to the protections of the Statute and, accordingly, the Financing Order is not revocable by the DTE; (iii) The Commonwealth of Massachusetts may not alter the provisions of the Statute that make the RTC Charge irrevocable and binding, limit or alter the Transition Property, the reimbursable transition costs amounts (as defined in Section 1H(a) of Chapter 164) or the Financing Order, and all rights thereunder, in a manner that would substantially impair the rights of the Certificateholders, absent a demonstration by The Commonwealth of Massachusetts that an impairment is narrowly-tailored and is necessary to advance an important public interest, such as a “great public calamity” until the Notes, together with interest thereon, are fully met and discharged; (iv) the DTE may not, either by rescinding, altering or amending the Financing Order, in any way reduce or impair the value of the Transition Property either directly or indirectly by taking reimbursable transition costs amounts into account when setting other rates for the Seller, in a manner that would substantially impair the rights of Certificateholders, absent a demonstration by The Commonwealth of Mass