EXHIBIT 4

PUBLIC SERVICE COMPANY

OF NEW HAMPSHIRE

AND

U.S. BANK NATIONAL ASSOCIATION,

Successor to WACHOVIA BANK, NATIONAL ASSOCIATION

and to FIRST UNION NATIONAL BANK

Formerly Known as FIRST FIDELITY BANK, NATIONAL ASSOCIATION,

NEW JERSEY

Successor to BANK OF NEW ENGLAND, NATIONAL ASSOCIATION

(Formerly Known as NEW ENGLAND MERCHANTS NATIONAL BANK)

and to

NEW BANK OF NEW ENGLAND, NATIONAL ASSOCIATION, TRUSTEE

TWENTY-FIRST SUPPLEMENTAL INDENTURE
Dated as of October 1, 2014

TO ISSUE SERIES S
FIRST MORTGAGE BONDS

$75,000,000 First Mortgage Bonds, Series S, due 2023

TABLE OF CONTENTS

Page

Date and Parties

Recitals

1

Granting Clauses

2

Exceptions

4

Habendum

5

Declaration in Trust

5

ARTICLE 1 – ADDITIONAL ISSUANCE OF SERIES S BONDS

1.01

Designation; Amount

5

1.02

Consent to Amendment and Restatement of Mortgage Indenture

5

ARTICLE 2 –MISCELLANEOUS PROVISIONS

2.01

Recitals

6

2.02

Benefits of Twenty-First Supplemental Indenture

6

2.03

Effect of Twenty-First Supplemental Indenture

6

2.04

Termination

6

2.05

Trust Indenture Act

6

2.06

Counterparts

6

2.07

Notices

7

Testimonium
Signatures

Schedule A

-

Description of Certain Properties Acquired Since November 1, 2013

Acknowledgments
Endorsement

i

THIS TWENTY-FIRST SUPPLEMENTAL INDENTURE dated as of October 1, 2014, between PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE (with its successors and assigns, the “Company”), a corporation duly organized and existing under the laws of the State of New Hampshire, having its principal place of business at Energy Park, 780 North Commercial Street in Manchester, New Hampshire 03101, and U.S. BANK NATIONAL ASSOCIATION (as successor to Wachovia Bank, National Association, and by merger to First Union National Bank, formerly known as First Fidelity Bank, National Association, New Jersey, successor in trust to Bank of New England, National Association (formerly known as New England Merchants National Bank) and to New Bank of New England, National Association), said U.S. BANK NATIONAL ASSOCIATION being a national banking association duly organized and existing under the laws of the United States of America having a corporate trust office at 21 South Street, Third Floor, Morristown, New Jersey 07960 and duly authorized to execute the trusts hereof (with its successors in trust, the “Trustee”), as trustee under the General and Refunding Mortgage Indenture, dated August 15, 1978 (as heretofore amended, including as amended and restated on June 1, 2011, being hereinafter generally called the “Mortgage Indenture” and, together with each and every prior indenture supplemental thereto and each and every other instrument, including this Twenty-First Supplemental Indenture, supplemental to the Mortgage Indenture, as the “Indenture”).

WHEREAS, the Company has previously executed and delivered to the Trustee twenty supplemental indentures which are part of the Indenture for the purposes recited therein and for the purpose of issuing bonds under the Indenture, the currently outstanding series of which are set forth in the following table:

1

*

These First Mortgage Bonds contain provisions for changes in the interest rate.

WHEREAS, the Company, by appropriate corporate action in conformity with the Mortgage Indenture, created a series of bonds designated as First Mortgage Bonds, 3.50% Series S due 2023 (hereinafter generally referred to as the “Series S Bonds” or the “bonds of Series S”);

WHEREAS, the terms and provisions of the Series S Bonds, and the form thereof, were set forth in the Twentieth Supplemental Indenture, dated as of November 1, 2013, between the Company and the Trustee (referred to as the “Twentieth Supplemental Indenture”), which Twentieth Supplemental Indenture also provided for the initial issuance of $250,000,000 aggregate principal amount of Series S Bonds;

WHEREAS, the Company desires to issue an additional Seventy-Five Million Dollars ($75,000,000) in aggregate principal amount of the Series S Bonds and the Company therefore proposes to execute and deliver this Twenty-First Supplemental Indenture (i) to provide for the issue of the additional bonds of Series S and confirm the lien of the Indenture on the property referred to below, all as permitted by Section 1301 of the Mortgage Indenture and (ii) to provide for the future amendment and restatement of the Mortgage Indenture as provided in Section 1.02 hereof;

WHEREAS, the Company has purchased, constructed or otherwise acquired certain additional property not heretofore specifically described in the Indenture but which is and is intended to be subject to the lien thereof, and proposes specifically to subject such additional property to the lien of the Indenture at this time;

WHEREAS, all acts and things necessary to make the issuance of the Series S Bonds, when executed by the Company and authenticated by the Trustee and delivered as in the Mortgage Indenture provided, the legal, valid and binding obligations of the Company according to their terms and to make this Twenty-First Supplemental Indenture a legal, valid and binding instrument for the security of the bonds, in accordance with its and their terms, have been done

2

and performed, and the execution and delivery of this Twenty-First Supplemental Indenture has in all respects been duly authorized;

NOW, THEREFORE, in consideration of the premises, and of the acceptance of said Series S Bonds by the holder thereof, and of the sum of $1.00 duly paid by the Trustee to the Company, and of other good and valuable considerations, the receipt whereof is hereby acknowledged, and in confirmation of and supplementing the Mortgage Indenture as previously supplemented, amended and restated by said twenty preceding supplemental indentures, and in performance of and compliance with the provisions thereof, said Public Service Company of New Hampshire, by these presents, does give, grant, bargain, sell, transfer, assign, pledge, mortgage and convey unto U.S. Bank National Association, as Trustee, as provided in the Mortgage Indenture, as previously supplemented, amended and restated and as supplemented by this Twenty-First Supplemental Indenture, and its successor or successors in the trust thereby and hereby created, and its and their assigns, (a) all and singular the property, and rights and interests in property, described in the Mortgage Indenture and the twenty preceding supplemental indentures and thereby conveyed, pledged, assigned, transferred and mortgaged, or intended so to be (said descriptions in said Mortgage Indenture being hereby made a part hereof to the same extent as if set forth herein at length), whether then or now owned or thereafter or hereafter acquired, except such of said properties or interests therein as may have been released or sold or disposed of in whole or in part as permitted by the provisions of the Mortgage Indenture, and (b) also, but without in any way limiting the generality of the foregoing, all the right, title and interest of the Company, now owned or hereafter acquired, in and to the rights, titles, interests and properties described or referred to in Schedule A hereto attached and hereby made a part hereof as fully as if set forth herein at length, in all cases not specifically reserved, excepted and excluded; the foregoing property, and rights and interests in property, being located in the following listed municipalities in New Hampshire and unincorporated areas in Coös County, New Hampshire, as well as in various municipalities in the States of Maine, Vermont and elsewhere:

BELKNAP COUNTY — Alton, Barnstead, Belmont, Center Harbor, Gilford, Gilmanton, Laconia, Meredith, New Hampton, Sanbornton, Tilton;

CARROLL COUNTY — Albany, Brookfield, Chatham, Conway, Eaton, Effingham, Freedom, Madison, Moultonboro, Ossipee, Sandwich, Tamworth, Tuftonboro, Wakefield, Wolfeboro;

CHESHIRE COUNTY — Alstead, Chesterfield, Dublin, Fitzwilliam, Gilsum, Harrisville, Hinsdale, Jaffrey, Keene, Marlborough, Marlow, Nelson, Richmond, Rindge, Roxbury, Stoddard, Sullivan, Surry, Swanzey, Troy, Westmoreland, Winchester;

COÖS COUNTY — Bean’s Grant, Berlin, Cambridge, Carroll, Chandler’s Purchase, Clarksville, Colebrook, Columbia, Crawford’s Purchase, Dalton, Dummer, Errol, Gorham, Green’s Grant, Jefferson, Lancaster, Martin’s Location, Milan, Millsfield, Northumberland, Pinkham’s Grant, Pittsburg, Randolph, Shelburne, Stark, Stewartstown, Stratford, Success, Thompson & Meserve’s Purchase, Wentworth’s Location, Whitefield;

3

GRAFTON COUNTY — Alexandria, Ashland, Bath, Bethlehem, Bridgewater, Bristol, Campton, Easton, Enfield, Franconia, Grafton, Hanover, Haverhill, Hebron, Holderness, Landaff, Lincoln, Lisbon, Littleton, Lyman, Lyme, Orange, Orford, Piermont, Plymouth, Rumney, Sugar Hill, Thornton, Woodstock;

HILLSBOROUGH COUNTY — Amherst, Antrim, Bedford, Bennington, Brookline, Deering, Francestown, Goffstown, Greenfield, Greenville, Hancock, Hillsborough, Hollis, Hudson, Litchfield, Lyndeborough, Manchester, Mason, Merrimack, Milford, Mont Vernon, Nashua, New Boston, New Ipswich, Pelham, Peterborough, Sharon, Temple, Weare, Wilton, Windsor;

MERRIMACK COUNTY — Allenstown, Andover, Boscawen, Bow, Bradford, Canterbury, Chichester, Concord, Danbury, Dunbarton, Epsom, Franklin, Henniker, Hill, Hooksett, Hopkinton, Loudon, Newbury, New London, Northfield, Pembroke, Pittsfield, Salisbury, Sutton, Warner, Webster, Wilmot;

ROCKINGHAM COUNTY — Auburn, Atkinson, Brentwood, Candia, Chester, Danville, Deerfield, Derry, East Kingston, Epping, Exeter, Fremont, Greenland, Hampstead, Hampton, Hampton Falls, Kensington, Kingston, Londonderry, New Castle, Newfields, Newington, Newmarket, Newton, North Hampton, Northwood, Nottingham, Portsmouth, Raymond, Rye, Sandown, Seabrook, South Hampton, Stratham, Windham;

STRAFFORD COUNTY — Barrington, Dover, Durham, Farmington, Lee, Madbury, Middleton, Milton, New Durham, Rochester, Rollinsford, Somersworth, Strafford;

SULLIVAN COUNTY — Charlestown, Claremont, Cornish, Croydon, Goshen, Grantham, Lempster, Newport, North Charleston, Plainfield, Springfield, Sunapee, Unity, Washington;

SUBJECT, HOWEVER, as to all of the foregoing, to the specific rights, privileges, liens, encumbrances, restrictions, conditions, limitations, covenants, interests, reservations, exceptions and otherwise as provided in the Mortgage Indenture, and in the descriptions in the schedules thereto and hereto and in the deeds or grants in said schedules referred to;

BUT SPECIFICALLY RESERVING, EXCEPTING AND EXCLUDING (as the same are reserved, excepted and excluded from the lien of the Mortgage Indenture) from this instrument and the grant, conveyance, mortgage, transfer and assignment herein contained, 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 (m), both inclusive, of the paragraph beginning “BUT SPECIFICALLY RESERVING, EXCEPTING AND EXCLUDING...” which paragraph is part of the granting clauses of the Mortgage Indenture;

TO HAVE AND TO HOLD all said plant, premises, property, franchises and rights 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;

4

BUT IN TRUST, NEVERTHELESS, with power of sale, for the equal pro rata benefit, security and protection of the owners of the bonds without any preference, priority or distinction whatever of any one bond over any other bond by reason of priority in the issue, sale or negotiation thereof, or otherwise;

PROVIDED, HOWEVER, and these presents are upon the condition, that if the Company shall pay or cause to be paid or make appropriate provision for the payment unto the holders of the bonds of the principal, premium, if any, and interest to become due thereon at the times and in the manner stipulated therein, and shall keep, perform and observe all and singular the covenants, agreements and provisions in the Indenture expressed to be kept, performed and observed by or on the part of the Company, then the Indenture and the estate and rights thereby and hereby granted shall, pursuant and subject to the provisions of Article 8 of the Mortgage Indenture, 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.: