SUMMARY

This summary highlights selected information contained in this joint proxy statement/prospectus, referred to as the joint proxy statement/prospectus, and does not contain all the information that may be important to you. Northeast Utilities and NSTAR urge you to read carefully this joint proxy statement/prospectus in its entirety, as well as the annexes. Additional, important information is also contained in the documents incorporated by reference into this joint proxy statement/prospectus; see the section entitled “Where You Can Find More Information; Incorporation By Reference” beginning on page 154.

The Companies

Northeast Utilities

Northeast Utilities, a voluntary association and Massachusetts business trust, is headquartered in Hartford, Connecticut and is a public utility holding company subject to the jurisdiction of the Federal Energy Regulatory Commission. Northeast Utilities is engaged primarily in the energy delivery business, providing franchised retail electric service to approximately 1.9 million customers in 419 cities and towns in Connecticut, New Hampshire and western Massachusetts through three of its wholly owned subsidiaries, The Connecticut Light and Power Company, Public Service Company of New Hampshire and Western Massachusetts Electric Company, and franchised retail natural gas service to approximately 200,000 residential, commercial and industrial customers in 71 cities and towns in Connecticut, through its wholly owned indirect subsidiary, Yankee Gas Services Company.

Northeast Utilities’ executive offices are located at 56 Prospect Street, Hartford, Connecticut 06103 and its telephone number is (860) 665-5000. Northeast Utilities common shares are listed on the NYSE and trade under the symbol “NU.”

This joint proxy statement/prospectus incorporates important business and financial information about Northeast Utilities from other documents that are incorporated by reference; see the section entitled “Where You Can Find More Information; Incorporation by Reference” beginning on page 154.

NSTAR

NSTAR, a voluntary association and Massachusetts business trust, is headquartered in Boston, Massachusetts. NSTAR is an energy delivery holding company serving approximately 1.4 million customers in Massachusetts. NSTAR conducts its business through operating subsidiaries. Its principal subsidiaries are NSTAR Electric Company, incorporated in 1886 under Massachusetts law, which serves approximately 1.1 million electric customers in 81 communities and NSTAR Gas Company, incorporated in 1851 under Massachusetts law, which serves approximately 300,000 natural gas distribution customers in 51 communities.

NSTAR also engages in unregulated businesses including telecommunications and liquefied natural gas service. Telecommunications services are provided through NSTAR Communications, Inc., which installs, owns, operates, and maintains a wholesale transport network for other telecommunications service providers in the metropolitan Boston area to deliver voice, video, data, and internet services to customers.

NSTAR’s executive offices are located at 800 Boylston Street, Boston, Massachusetts 02199 and its telephone number is (617) 424-2000. NSTAR common shares are listed on the NYSE and trade under the symbol “NST.”

This joint proxy statement/prospectus incorporates important business and financial information about NSTAR from other documents that are incorporated by reference; see the section entitled “Where You Can Find More Information; Incorporation by Reference” beginning on page 154.

NU Holding Energy 1 LLC

NU Holding Energy 1 LLC, or Merger Sub, a direct wholly owned subsidiary of Northeast Utilities, is a Massachusetts limited liability corporation formed on October 14, 2010 for the purpose of effecting transactions related to the merger. NU Holding Energy 1 LLC has not conducted any activities other than those incidental to its formation and the matters contemplated by the merger agreement, including the preparation of applicable regulatory filings in connection with the merger.

NU Holding Energy 2 LLC

NU Holding Energy 2 LLC, or Acquisition Sub, a direct wholly owned subsidiary of Northeast Utilities, is a Massachusetts limited liability corporation formed on October 14, 2010 for the purpose of effecting transactions related to the merger. NU Holding Energy 2 LLC has not conducted any activities other than those incidental to its formation and the matters contemplated by the merger agreement, including the preparation of applicable regulatory filings in connection with the merger.

The Merger

On October 16, 2010, the boards of trustees of Northeast Utilities and NSTAR each unanimously approved the merger agreement and the merger. Under the terms and conditions of the merger agreement, and in accordance with Massachusetts law, Merger Sub will be merged with and into NSTAR, with NSTAR surviving. Immediately thereafter, NSTAR will be merged with and into Acquisition Sub, with Acquisition Sub surviving. When these mergers are consummated, Acquisition Sub will be renamed NSTAR LLC and survive as a wholly owned subsidiary of Northeast Utilities. For more information on the merger, see the section entitled “The Merger” beginning on page 35.

Consideration to be Received in the Merger by NSTAR Shareholders

As a result of the merger, each NSTAR shareholder will receive 1.312 common shares of Northeast Utilities for each NSTAR common share held. Shareholders of NSTAR will receive cash in lieu of fractional shares, as applicable. Northeast Utilities shareholders will continue to own their existing common shares, which will not be exchanged in the merger.

Treatment of Stock Options and Other Stock-based Awards

Northeast Utilities

Subject to adoption of the merger agreement and approval of the merger by the Northeast Utilities shareholders (i) restricted share units held by employees will be immediately vested in full (or on a pro-rated basis, if at least age 65 upon employment termination, for awards granted during the year of termination), and distributed in Northeast Utilities common shares six months following a qualifying termination of employment (a termination of employment for “good reason” or without “cause”), (ii) restricted share units held by non-employee members of the Northeast Utilities board of trustees will vest upon any termination of service other than for “cause” and (subject to any applicable deferral election) will be distributed in full to any trustee whose service terminates after attaining age 65 and on a pro-rated basis to any trustee who has not yet reached

age 65, and (iii) upon completion of the merger, the extent of satisfaction of the performance goals applicable to performance units (performance shares and performance cash) held by employees for any performance periods not yet completed generally will be measured based on performance through completion of the merger and payment generally will be made on a pro-rata basis (based on the portion of the applicable performance period that had been completed upon completion of the merger) following the end of the original performance period conditioned upon continued employment through such date (provided that, if an executive officer experiences a qualifying termination of employment before completion of the original performance period, the awards will be vested at target performance levels and paid out without pro-ration upon such termination). All outstanding Northeast Utilities share options are vested and will remain outstanding in accordance with their terms.

NSTAR

Under the NSTAR equity incentive compensation plans, (i) upon completion of the merger, each stock option will convert into a fully vested option to acquire, on the same terms and conditions as otherwise were applicable to the NSTAR option prior to the merger (including accelerated vesting that occurs as a result of the merger), a number of Northeast Utilities common shares equal to the product of the number of NSTAR common shares subject to the NSTAR option and the exchange ratio, rounded down to the nearest whole share of Northeast Utilities common share, at an exercise price per Northeast Utilities common share equal to the quotient obtained by dividing the per share exercise price of the NSTAR option by the exchange ratio, rounded up to the nearest whole cent, (ii) outstanding performance share awards will be deemed earned at the target performance level and will be settled immediately prior to the completion of the merger, and (iii) the restrictions and conditions on all other outstanding awards will automatically lapse or be deemed waived. However, stock-based awards granted after the execution of the merger agreement will not vest upon the completion of the merger and will instead be substituted upon completion of the merger for equivalent equity awards denominated in Northeast Utilities shares. For additional information regarding the treatment of NSTAR equity incentive compensation awards, see the section entitled “The Merger — Treatment of NSTAR Options and Equity-based Awards” beginning on page 91.

Northeast Utilities Board of Trustees and Executive Officers After the Merger

Board of Trustees. The merger agreement provides that, following the merger, the board of trustees of the combined company will consist of fourteen members including: (a) seven designees of Northeast Utilities (which will include Charles W. Shivery, chairman, president and chief executive officer of Northeast Utilities); and (b) seven designees of NSTAR (which will include Thomas J. May, chairman, president and chief executive officer of NSTAR).

Chairman. Upon completion of the merger, Mr. Shivery will serve as non-executive chairman of the combined company for a period of 18 months at which time Mr. May will become chairman of the combined company.

Executive Officers. Upon completion of the merger, the corporate leadership team of the combined company will consist of Mr. May as president and chief executive officer; Gregory B. Butler as senior vice president and general counsel; Christine M. Carmody as senior vice president of human resources; James J. Judge as executive vice president and chief financial officer; David R. McHale as executive vice president and chief administrative officer; Joseph R. Nolan, Jr. as senior vice president of corporate relations; and Leon J. Olivier as executive vice president and chief operating officer.

For a more complete discussion of the trustees and executive officers of the combined company, see the section entitled “The Merger — Corporate Governance Following the Merger” on page 81.

Recommendation of Northeast Utilities’ Board of Trustees

After careful consideration, the Northeast Utilities board of trustees recommends that Northeast Utilities shareholders vote “FOR” the adoption of the merger agreement and approval of the merger, including the issuance of Northeast Utilities common shares to NSTAR shareholders pursuant to the merger, “FOR” the proposal to increase the number of Northeast Utilities common shares authorized for issuance, “FOR” the proposal to fix the number of trustees of the Northeast Utilities board of trustees at fourteen and “FOR” the proposal to adjourn the Northeast Utilities special meeting, if necessary or appropriate, to solicit additional proxies in favor of such proposals.

For a more complete description of Northeast Utilities’ reasons for the merger and the recommendations of the Northeast Utilities board of trustees, see the section entitled “The Merger — Northeast Utilities’ Reasons for the Merger; Recommendation of Northeast Utilities’ Board of Trustees” beginning on page 45.

Recommendation of NSTAR’s Board of Trustees

After careful consideration, the NSTAR board of trustees recommends that NSTAR shareholders vote “FOR” the adoption of the merger agreement and approval of the merger and “FOR” the proposal to adjourn the NSTAR special meeting, if necessary or appropriate, to solicit additional proxies in favor of such proposal.

For a more complete description of NSTAR’s reasons for the merger and the recommendations of the NSTAR’s board of trustees, see the section entitled “The Merger — NSTAR’s Reasons for the Merger; Recommendation of NSTAR’s Board of Trustees” beginning on page 65.

Opinions of the Financial Advisors

Northeast Utilities Financial Advisors

Barclays Capital Inc.

On October 16, 2010, at a meeting of the Northeast Utilities board of trustees held to evaluate the proposed merger, Barclays Capital Inc., which is referred to as Barclays Capital, delivered its opinion to the Northeast Utilities board of trustees that, as of October 16, 2010 and based upon and subject to the qualifications, limitations and assumptions stated in its opinion, the exchange ratio was fair, from a financial point of view, to Northeast Utilities.

The full text of Barclays Capital’s written opinion, dated as of October 16, 2010, is attached as Annex B to this joint proxy statement/prospectus. Barclays Capital’s written opinion sets forth, among other things, the assumptions made, procedures followed, factors considered and limitations upon the review undertaken by Barclays Capital in rendering its opinion. This summary of Barclays Capital’s written opinion is qualified in its entirety by reference to the full text of the opinion. Barclays Capital’s opinion is addressed to the Northeast Utilities board of trustees for its use in connection with its evaluation of the proposed merger. Barclays Capital’s opinion relates only to the fairness, from a financial point of view, to Northeast Utilities of the exchange ratio and does not constitute a recommendation to any shareholder of Northeast Utilities or NSTAR as to how such shareholder should vote or act with respect to the proposed merger or any other matter.

Lazard Frères & Co. LLC.

Lazard Frères & Co. LLC, which is referred to as Lazard, delivered its opinion to the Northeast Utilities board of trustees that, as of October 16, 2010, and based upon and subject to the assumptions, procedures, factors, qualifications and limitations set forth therein, the exchange ratio of 1.312 was fair, from a financial point of view, to Northeast Utilities.

The full text of Lazard’s written opinion, dated October 16, 2010, which set forth the assumptions made, procedures followed, factors considered, and qualifications and limitations on the review undertaken by Lazard in connection with its opinion, is attached hereto as Annex C to this joint proxy statement/prospectus and is incorporated herein by reference. Lazard’s opinion was directed to the Northeast Utilities board of trustees for the information and assistance of the Northeast Utilities board of trustees in connection with its evaluation of the merger and addressed only the fairness as of the date of the opinion, from a financial point of view, of the exchange ratio to Northeast Utilities. Lazard’s opinion was not intended to, and does not constitute, a recommendation to any holder of Northeast Utilities common shares or NSTAR common shares as to how such holder should vote or act with respect to the merger or any matter relating thereto.

NSTAR Financial Advisors

Goldman, Sachs & Co.

At the meeting of the NSTAR board of trustees held on October 16, 2010, Goldman, Sachs & Co., which is referred to as Goldman Sachs, delivered its oral opinion to the NSTAR board of trustees, which it subsequently confirmed by delivery of its written opinion dated October 16, 2010, that, as of October 16, 2010 and based upon and subject to the factors and assumptions set forth therein, the exchange ratio pursuant to the merger agreement was fair from a financial point of view to the holders (other than Northeast Utilities and its affiliates) of NSTAR common shares.

The full text of the written opinion of Goldman Sachs, dated October 16, 2010, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex D. Goldman Sachs provided its opinion for the information and assistance of NSTAR’s board of trustees in connection with its consideration of the merger. The Goldman Sachs opinion is not a recommendation as to how any holder of NSTAR common shares should vote with respect to the merger or any other matter.

Lexicon Partners (US) LLC

In connection with the merger, Lexicon Partners (US) LLC, which is referred to as Lexicon Partners, delivered a written opinion, dated October 16, 2010, to the NSTAR board of trustees as to the fairness, from a financial point of view and as of such date, to holders of NSTAR common shares of the exchange ratio provided for in the merger.

The full text of Lexicon Partners’ written opinion, which sets forth, among other things, the assumptions made, procedures followed, matters considered, and qualifications and limitations on the opinion and the review undertaken in connection with rendering its opinion, is included as Annex E to this joint proxy statement/prospectus. Lexicon Partners’ opinion was provided to the NSTAR board of trustees (in its capacity as such) in connection with and for the purposes of its evaluation of the merger and addressed only the fairness, from a financial point of view, of the exchange ratio and no other matters. The opinion does not constitute a recommendation to any shareholder as to how any shareholder should vote or act with respect to the merger or any related matter.

Additional Interests of Trustees and Executive Officers in the Merger

Northeast Utilities’ and NSTAR’s executive officers and trustees have interests in the merger that may be different from, or in addition to, the interests of Northeast Utilities and NSTAR shareholders generally. Northeast Utilities’ executive officers negotiated the terms of the merger agreement with NSTAR’s executive officers. The executive officers have arrangements with Northeast Utilities or NSTAR, as applicable, that provide for severance benefits if their employment is terminated under certain circumstances following the completion of the

merger. In addition, certain of Northeast Utilities’ and NSTAR’s compensation and benefit plans and arrangements provide for payment or accelerated vesting or distribution of certain rights or benefits upon completion of the merger (and, in some cases, upon shareholder approval of the merger agreement). Executive officers and trustees of Northeast Utilities and NSTAR also have rights to indemnification and directors’ and officers’ liability insurance that will survive the completion of the merger.

Moreover, Charles W. Shivery, currently chairman, president and chief executive officer of Northeast Utilities, will serve as non-executive chairman of the board of the combined company for eighteen months after completion of the merger. Thomas J. May, currently chairman, president and chief executive officer of NSTAR, will serve as the chief executive officer of the combined company, and will succeed Mr. Shivery as chairman of the board eighteen months after completion of the merger. Immediately following the effective time of the merger, the board of trustees of the combined company will consist of fourteen members, including seven designees of Northeast Utilities, including Mr. Shivery, and seven designees of NSTAR, including Mr. May.

The Northeast Utilities and NSTAR boards of trustees were aware of these interests at the time each approved the merger and the transactions contemplated by the merger agreement. These interests may cause Northeast Utilities’ and NSTAR’s trustees and executive officers to view the NSTAR merger proposal differently than you may view it as a shareholder. See the sections entitled “The Merger — Additional Interests of Northeast Utilities Trustees and Executive Officers in the Merger” and “The Merger — Additional Interests of NSTAR Trustees and Executive Officers in the Merger,” beginning on pages 82 and 86, respectively, for more information.

Material United States Federal Income Tax Consequences of the Merger

It is a condition to the merger that both Northeast Utilities and NSTAR receive legal opinions from their respective legal counsel to the effect that for United States federal income tax purposes the merger will qualify as a “reorganization” within the meaning of Section 368(a) of the Code. In addition, in connection with the registration statement of which this joint proxy statement/prospectus is a part being declared effective, each of Skadden, Arps, Slate, Meagher & Flom LLP, counsel to Northeast Utilities and which is referred to as Skadden, Arps in this joint proxy statement/prospectus, and Ropes & Gray LLP, counsel to NSTAR and which is referred to as Ropes & Gray in this joint proxy statement/prospectus, will deliver an opinion to Northeast Utilities and NSTAR, respectively, to the same effect as the opinions described above. Provided that the merger qualifies as a “reorganization” within the meaning of Section 368(a) of the Code, an NSTAR shareholder will not recognize gain or loss for United States federal income tax purposes as a result of such shareholder’s NSTAR common shares being exchanged in the merger for shares of Northeast Utilities, except with respect to the receipt of cash in lieu of a fractional share of Northeast Utilities.

The discussion of material United States federal income tax consequences of the merger contained in this joint proxy statement/prospectus is intended to provide only a general summary and is not a complete analysis or description of all potential United States federal income tax consequences of the merger. The discussion does not address tax consequences that may vary with, or are contingent on, individual circumstances. In addition, it does not address the effects of any state, local, non-United States or non-income tax laws.

NSTAR shareholders are strongly urged to consult with their tax advisors regarding the tax consequences of the merger to them, including the effects of United States federal, state, local, non-United States and other tax laws.

For a more complete description of the material United States federal income tax consequences of the merger, see the section entitled “Material United States Federal Income Tax Consequences” beginning on page 94.

Accounting Treatment of the Merger

Accounting standards require that one party to the merger be identified as the acquirer. Therefore, the merger of Northeast Utilities and NSTAR will be accounted for as an acquisition of NSTAR common shares by Northeast Utilities in accordance with generally accepted accounting principles of the United States, which we refer to as GAAP. This means that the assets and liabilities of NSTAR will be recorded, as of the completion of the merger, at their fair values and added to those of Northeast Utilities, including an amount for goodwill representing the amount that the purchase price exceeds the fair value of the identifiable net assets. Financial statements of Northeast Utilities issued after the merger will reflect only the operations of NSTAR’s businesses after the merger and will not be restated retroactively to reflect the historical financial position or results of NSTAR.

For more information regarding the accounting treatment of the transaction see the section entitled “The Merger — Accounting Treatment” beginning on page 90.

Appraisal Rights

Northeast Utilities shareholders will not have any appraisal or dissenters’ rights as a result of the merger.

Neither NSTAR’s declaration of trust nor Chapter 182 of the M.G.L., which governs voluntary associations such as NSTAR, authorizes appraisal or dissenters’ rights for shareholders. NSTAR believes that NSTAR shareholders are not entitled to appraisal rights in connection with the merger. However, the question of whether Massachusetts law would apply corporate appraisal rights to voluntary associations has not been the subject of specific judicial interpretation. If you believe you are entitled to appraisal rights, you should consult your legal advisor.

Regulatory Matters

To complete the merger, Northeast Utilities and NSTAR must make filings with and obtain authorizations, approvals or consents from federal and state public utility, antitrust and other regulatory authorities. For a more complete discussion of regulatory matters relating to the merger, see the section entitled “Regulatory Matters Relating to the Merger” on beginning on page 97.

Litigation Relating to the Merger

In connection with the merger, NSTAR, Northeast Utilities, the members of the NSTAR board of trustees, and two wholly owned subsidiaries of Northeast Utilities, NU Holding Energy 1 LLC and NU Holding Energy 2 LLC, were named defendants in eight lawsuits filed in the Superior Court for Suffolk County, Massachusetts, and one lawsuit filed in federal court in the district of Massachusetts. The lawsuits purport to be brought on behalf of classes of NSTAR shareholders opposed to the terms of the merger agreement. The complaints allege, among other things, that NSTAR’s trustees breached their fiduciary duties by failing to maximize the value to be received by NSTAR’s shareholders, and that the other defendants aided and abetted the NSTAR trustees’ breaches of fiduciary duties. The complaints seek, among other things, to enjoin defendants from consummating the merger and either rescission of the merger, to the extent it is completed, or monetary damages. NSTAR and Northeast Utilities believe that all nine lawsuits are without merit and intend to defend the lawsuits vigorously.

For more information regarding the litigation related to the merger see the sections entitled “Risk Factors” beginning on page 28 and “Litigation Relating to the Merger” on page 93.

Overview of the Merger Agreement

A copy of the merger agreement, as amended, is attached as Annex A to this joint proxy statement/prospectus. We encourage you to read the entire merger agreement carefully because it is the principal document governing the merger. For more information on the merger agreement, see the section entitled “The Merger Agreement” beginning on page 100.

Conditions to Completion of the Merger

A number of conditions must be satisfied or waived, before the merger can be completed. These include, among others:

For more information regarding conditions to the completion of the merger and a complete list of such conditions, see the section entitled “The Merger Agreement — Conditions to Completion of the Merger” beginning on page 102.

No Solicitation

Neither Northeast Utilities nor NSTAR, nor any of their respective subsidiaries, officers, trustees, directors, employees, counsel, financial advisors or other representatives will, and each will use its reasonable efforts not to, directly or indirectly, take any of the following actions:

However, Northeast Utilities or NSTAR may, as applicable, prior to receiving their respective shareholder approvals required to consummate the merger, and subject to certain notice and other requirements, participate or engage in discussions or negotiations with, or disclose nonpublic information with respect to itself and its subsidiaries, to a third party that makes an unsolicited, bona fide acquisition proposal that the board of trustees of Northeast Utilities or NSTAR, as applicable, determines in good faith after consultation with its legal and financial advisors is, or would be reasonably likely to lead to, a superior proposal, under certain circumstances.

In addition, Northeast Utilities or NSTAR may, as applicable, prior to receiving their respective shareholder approvals required to consummate the merger, and subject to certain notice and other requirements, make an adverse recommendation and terminate the merger agreement in response to a material development or change in circumstances occurring or arising after the date of the merger agreement that was neither known to the applicable party’s board of trustees nor reasonably foreseeable on the date of the merger agreement, independent of any acquisition proposal, if the applicable board of trustees determines in good faith after consultation with its legal counsel that the failure to make an adverse recommendation change would be inconsistent with its fiduciary obligations.

For more information regarding the limitations on the ability of Northeast Utilities and NSTAR and their respective boards to consider other proposals, see the section entitled “The Merger Agreement — No Solicitation” on page 108.

Termination of the Merger Agreement

The merger agreement may be terminated at any time by mutual written agreement of Northeast Utilities and NSTAR. It can also be terminated by either Northeast Utilities or NSTAR under several specific circumstances, including:

For more information regarding termination of the merger agreement, see the section entitled “The Merger Agreement — Termination” beginning on page 112.

Termination Fee and Expense Reimbursement

The merger agreement provides that, upon a termination of the merger agreement under specified circumstances, Northeast Utilities or NSTAR, as the case may be, may be required to pay a termination fee of approximately $135 million, plus up to $35 million for out of pocket fees and expenses incurred or paid by the party receiving payment of the termination fee.

For more information regarding termination fees and expense reimbursement obligations, see the section entitled “The Merger Agreement — Effect of Termination; Termination Fee” beginning on page 113.

The Shareholders’ Meetings

Northeast Utilities

The Northeast Utilities special meeting will be held on [—], at [—], local time at the [—]. For more information about the Northeast Utilities special meeting, see the section entitled “Northeast Utilities Special Meeting” beginning on page 118.

At the Northeast Utilities special meeting, the Northeast Utilities shareholders will be asked to consider and vote upon the following proposals:

Only holders of record of Northeast Utilities common shares at the close of business on [—], the Northeast Utilities special meeting record date, are entitled to notice of, and to vote at, the Northeast Utilities special meeting and at any adjournments or postponements of the Northeast Utilities special meeting. At the close of business on the record date, there were [—] common shares of Northeast Utilities outstanding and entitled to vote at the Northeast Utilities special meeting.

The affirmative vote of the holders of two-thirds of the Northeast Utilities common shares outstanding and entitled to vote is required to approve the merger proposal.

The affirmative vote of the holders of a majority of the Northeast Utilities common shares outstanding and entitled to vote is required to approve the share authorization proposal.

The affirmative vote of the holders of a majority of the Northeast Utilities common shares outstanding and entitled to vote is required to fix the number of trustees of the Northeast Utilities board of trustees at fourteen.

NSTAR

The NSTAR special meeting will be held on [—], at [—], local time, at the [—]. For more information about the NSTAR special meeting, see the section entitled “NSTAR Special Meeting” beginning on page 126.

At the NSTAR special meeting, the NSTAR shareholders will be asked to consider and vote upon:

Only holders of record of NSTAR common shares at the close of business on [—], the NSTAR special meeting record date, are entitled to notice of, and to vote at, the NSTAR special meeting and at any adjournments or postponements of the NSTAR special meeting. At the close of business on the record date, there were [—] common shares of NSTAR outstanding and entitled to vote at the NSTAR special meeting.

The affirmative vote of the holders of two-thirds of the NSTAR common shares outstanding and entitled to vote is required to approve the merger proposal.

Voting by Northeast Utilities and NSTAR Trustees and Executive Officers

At the close of business on [—], the record date for the Northeast Utilities special meeting, trustees and executive officers of Northeast Utilities had the right to vote less than [—]% of the then outstanding Northeast Utilities common shares. Each Northeast Utilities trustee and executive officer has indicated his or her present intention to vote, or cause to be voted, the Northeast Utilities common shares owned by him or her for the approval of the above proposals.

At the close of business on [—], the record date for the NSTAR special meeting, trustees and executive officers of NSTAR had the right to vote less than [—]% of the then outstanding NSTAR shares. Each NSTAR trustee and executive officer has indicated his or her present intention to vote, or cause to be voted, the NSTAR shares owned by him or her for the adoption of the merger agreement and approval of the merger.

SELECTED HISTORICAL FINANCIAL DATA OF NORTHEAST UTILITIES

The selected historical consolidated financial data of Northeast Utilities for each of the years ended December 31, 2009, 2008 and 2007 and as of December 31, 2009 and 2008 have been derived from Northeast Utilities’ audited consolidated financial statements contained in its Annual Report on Form 10-K for the year ended December 31, 2009, which is incorporated by reference in this joint proxy statement/prospectus. The selected historical consolidated financial data as of September 30, 2010 and for the nine months ended September 30, 2010 and 2009 have been derived from Northeast Utilities’ unaudited condensed consolidated financial statements as of such dates and for those periods, which have been incorporated by reference in this joint proxy statement/prospectus. The selected historical consolidated financial data for the years ended December 31, 2006 and 2005 and as of September 30, 2009 and December 31, 2007, 2006 and 2005 have been derived from Northeast Utilities’ consolidated financial statements as of such dates and for those years, which have not been incorporated by reference in this joint proxy statement/prospectus. The information set forth below is only a summary and is not necessarily indicative of the results of future operations of Northeast Utilities or the combined company, and you should read the following information together with Northeast Utilities’ audited consolidated financial statements, the related notes and the section entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in Northeast Utilities’ Annual Report on Form 10-K for the year ended December 31, 2009, which is incorporated by reference in this joint proxy statement/prospectus. For more information, see the section entitled “Where You Can Find More Information; Incorporation By Reference” beginning on page 154.

SELECTED HISTORICAL FINANCIAL DATA OF NSTAR

The selected historical consolidated financial data of NSTAR for each of the years ended December 31, 2009, 2008 and 2007 and as of December 31, 2009 and 2008 have been derived from NSTAR’s audited consolidated financial statements contained in its Annual Report on Form 10-K for the year ended December 31, 2009, which is incorporated by reference in this joint proxy statement/prospectus. The selected historical consolidated financial data as of September 30, 2010 and for the nine months ended September 30, 2010 and 2009 have been derived from NSTAR’s unaudited condensed consolidated financial statements as of such dates and for those periods, which have been incorporated by reference in this joint proxy statement/prospectus. The selected historical consolidated financial data for the years ended December 31, 2006 and 2005 and as of September 30, 2009 and December 31, 2007, 2006 and 2005 have been derived from NSTAR’s consolidated financial statements as of such dates and for those years, which have not been incorporated by reference in this joint proxy statement/prospectus. The information set forth below is only a summary and is not necessarily indicative of the results of future operations of NSTAR or the combined company, and you should read the following information together with NSTAR’s audited consolidated financial statements, the related notes and the section entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in NSTAR’s Annual Report on Form 10-K for the year ended December 31, 2009, which is incorporated by reference in this joint proxy statement/prospectus. For more information, see the section entitled “Where You Can Find More Information; Incorporation By Reference” beginning on page 154.

SUMMARY UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL DATA

The following selected unaudited pro forma condensed combined consolidated statement of income data of Northeast Utilities for the nine months ended September 30, 2010 and for the year ended December 31, 2009 have been prepared to give effect to the merger as if the merger had been completed on January 1, 2009. The unaudited pro forma condensed combined consolidated balance sheet data of Northeast Utilities as of September 30, 2010 has been prepared to give effect to the merger as if the merger had been completed on September 30, 2010.

The following selected unaudited pro forma condensed combined consolidated financial information is not necessarily indicative of the results that might have occurred had the merger taken place on January 1, 2009 for income statement purposes, or on September 30, 2010 for balance sheet purposes, and is not intended to be a projection of future results. Future results may vary significantly from the results reflected because of various factors, including those discussed in the section entitled “Risk Factors” beginning on page 28. The following selected unaudited pro forma condensed combined consolidated financial information should be read in conjunction with the section entitled “Unaudited Pro Forma Condensed Combined Consolidated Financial Statements” and related notes included in this joint proxy statement/prospectus beginning on page 132.

COMPARATIVE PER SHARE DATA (UNAUDITED)

The following table summarizes unaudited per share data for (a) Northeast Utilities and NSTAR on a historical basis, (b) Northeast Utilities on a pro forma combined basis giving effect to the merger and (c) NSTAR on a pro forma equivalent basis based on the exchange ratio of 1.312 common shares of Northeast Utilities per common share of NSTAR. It has been assumed for purposes of the pro forma combined financial information provided below that the merger was completed on January 1, 2009 for earnings per share purposes, and on September 30, 2010 for book value per share purposes. The following information should be read in conjunction with the section entitled “Unaudited Pro Forma Condensed Combined Consolidated Financial Statements” and related notes included in this joint proxy statement/prospectus beginning on page 132.