# EDGAR Filing Document

**Accession Number:** 0000755001
**File Stem:** 0001193125-26-029469
**Filing Date:** 2026-1
**Character Count:** 12787
**Document Hash:** ba55c3e8802ee50067d6a5581f1e96ed
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-029469.hdr.sgml**: 20260129

**ACCESSION NUMBER**: 0001193125-26-029469

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 13

**CONFORMED PERIOD OF REPORT**: 20260123

**ITEM INFORMATION**: Entry into a Material Definitive Agreement

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260129

**DATE AS OF CHANGE**: 20260129

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** UNITIL CORP
- **CENTRAL INDEX KEY:** 0000755001
- **STANDARD INDUSTRIAL CLASSIFICATION:** ELECTRIC & OTHER SERVICES COMBINED [4931]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 020381573
- **STATE OF INCORPORATION:** NH
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-08858
- **FILM NUMBER:** 26578512

**BUSINESS ADDRESS:**
- **STREET 1:** 6 LIBERTY LANE WEST
- **CITY:** HAMPTON
- **STATE:** NH
- **ZIP:** 03842
- **BUSINESS PHONE:** 6037736504

**MAIL ADDRESS:**
- **STREET 1:** 6 LIBERTY LANE WEST
- **CITY:** HAMPTON
- **STATE:** NH
- **ZIP:** 03842

?xml version='1.0' encoding='ASCII'? 8-K

### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

### FORM 8-K

#### CURRENT REPORT

#### Pursuant to Section 13 or 15(d)

#### of the Securities Exchange Act of 1934

#### Date of Report (Date of earliest event reported): January 23, 2026

## UNITIL CORPORATION

#### (Exact name of registrant as specified in its charter)

---

| | | |
|:---|:---|:---|
| **New Hampshire** | **1-8858** | **02-0381573** |
| **(State or other jurisdiction**<br> **of incorporation)** | **(Commission**<br> **File Number)** | **(IRS Employer**<br> **Identification No.)** |

---

---

| | |
|:---|:---|
| **6 Liberty Lane West, Hampton, New Hampshire** | **03842-1720** |
| **(Address of principal executive offices)** | **(Zip Code)** |

---

#### Registrant's telephone number, including area code: (603) 772-0775

#### N/A

#### (Former name or former address, if changed since last report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

---

| | | |
|:---|:---|:---|
| **Title of each class** | **Trading**<br> **Symbol** | **Name of each exchange**<br> **on which registered** |
| Common Stock, no par value | UTL | New York Stock Exchange |

---

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

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| | |
|:---|:---|
| **Item 1.01** | **Entry into a Material Definitive Agreement**  |

---

#### Amendment to Purchase Agreement
On May 6, 2025, Unitil Corporation, a New Hampshire corporation (the "**Company**"), entered into a Purchase and Sale Agreement (the "**Purchase Agreement**") by and between the Company and Aquarion Water Authority, a public corporation and political subdivision of the state of Connecticut ("**Seller**"), and, solely with respect to Section 9.25 and Section 9.26 thereof, South Central Connecticut Regional Water Authority ("**RWA**"). Pursuant to the Purchase Agreement, the Company agreed to acquire all of the issued and outstanding shares of common stock of Aquarion Water Company of Massachusetts, Inc., Aquarion Water Company of New Hampshire, Inc., and Abenaki Water Co., Inc. from Seller (the "**Acquisition**").

The Company previously disclosed a brief summary of the material terms and conditions of the Purchase Agreement in a Form 8-K dated May 6, 2025, which the Company filed with the Securities and Exchange Commission on May 12, 2025.

On January 23, 2026, the Company entered into an Amendment No. 1 to Purchase and Sale Agreement (the "**Amendment**") by and between the Company, Seller and RWA. The Amendment, among other things, amends the definition of "Termination Date" in Section 8.1(d) of the Purchase Agreement by replacing the reference to "January 23, 2026" with "February 23, 2026". Except as specifically modified and amended by the Amendment, the Purchase Agreement remains unchanged.

Neither the Company nor any of its controlled affiliates has any material relationship with Seller or RWA, other than with respect to the Purchase Agreement and the Amendment.

The foregoing summary of the Amendment does not purport to be complete and is subject to, and qualified in its entirety by, the full text of the Amendment attached hereto as Exhibit 2.1.

The Amendment has been included to provide investors with information regarding its terms. The Amendment is not intended to provide any factual information about the Company. The representations, warranties and covenants contained in the Amendment were made only for purposes of the Amendment and as of specific dates and were solely for the benefit of the parties to the Amendment. Moreover, the representations and warranties contained in the Amendment generally were made for the purpose of allocating contractual risk among the parties to the Amendment instead of establishing matters as facts, and may be subject to standards of materiality applicable to the parties to the Amendment that differ from those applicable to investors. Investors are not third-party beneficiaries under the Amendment and should not rely on the representations, warranties and covenants contained therein or any descriptions thereof as characterizations of the actual state of facts or condition of the Company or any of its subsidiaries or affiliates. Additionally, information concerning the subject matter of the representations and warranties contained in the Amendment may change after the date of the Amendment, which subsequent information may or may not be fully reflected in the Company's public disclosures.

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| | |
|:---|:---|
| **Item 9.01** | **Financial Statements and Exhibits**  |

---

(d) Exhibits

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| | | |
|:---|:---|:---|
| Number | Exhibit | Reference (1) |
| 2.1 | [Amendment No. 1 to Purchase and Sale Agreement, dated as of January 23, 2026, by and among Unitil Corporation, Aquarion Water Authority and South Central Connecticut Regional Water Authority.](d18575dex21.htm) | Filed herewith |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document) | Filed herewith |

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(1) The exhibits referred to in this column by specific designations and dates have heretofore been filed with or furnished to the Securities and Exchange Commission under such designations and are hereby incorporated by reference.

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#### SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

---

| |
|:---|
| UNITIL CORPORATION |
| By: |
| /s/ Daniel J. Hurstak |
| Daniel J. Hurstak |
| Senior Vice President, Chief Financial Officer and Treasurer |

---

Date: January 29, 2026

## Exhibit 2.1

**Exhibit 2.1** 

EXECUTION VERSION

**AMENDMENT NO. 1 TO PURCHASE AND SALE AGREEMENT** 

This Amendment No. 1 to Purchase and Sale Agreement (this "**Amendment**"), dated as of January 23, 2026 (the "**Effective Date**"), is by and among Unitil Corporation, a New Hampshire corporation ("**Buyer**"), Aquarion Water Authority, a public corporation and political subdivision of the state of Connecticut ("**Seller**"), and South Central Connecticut Regional Water Authority ("**RWA**"). Buyer, Seller and RWA will be referred to herein from time to time collectively as the "**Parties**". Each capitalized term used and not defined herein has the meaning set forth in the Purchase and Sale Agreement.

**WHEREAS**, the Parties are parties to that certain Purchase and Sale Agreement, dated as of May 6, 2025 (the "**Agreement**");

**WHEREAS**, subject to the terms and conditions set forth in this Amendment, and pursuant to Section 9.19 of the Agreement, the Parties desire to amend certain terms of the Agreement by entering into this Amendment.

**NOW, THEREFORE**, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and intending to be legally bound, the Parties agree as follows:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. <u>Termination Date</u>. Section 8.1(d) of the Agreement is hereby amended by replacing reference to
"January 23, 2026" with "February 23, 2026".

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. <u>Amendment to Eversource Agreement</u>. The Parties acknowledge and agree that Seller, in accordance with,
and in satisfaction of, Section 6.20 of the Agreement, hereby delivers notice of amendment of the Eversource Agreement pursuant to, and as set forth in, that certain Amendment No. 1 to Purchase and Sale Agreement, dated as of
January 23, 2026, by and between Eversource, Seller and RWA.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. <u>Representations and Warranties</u>. Each Party hereby represents and warrants that it has all necessary
power and authority to execute and deliver this Amendment and perform its obligations hereunder and to consummate the transactions contemplated hereby. The execution, delivery and performance of this Amendment by such Party and the consummation of
the transactions contemplated hereby have been duly authorized by all necessary action on the part of such Party and no further authorization, consent or similar action on the part of any equityholders or the authority board, as applicable, of such
Party is necessary to authorize the execution, delivery and performance by such Party of this Amendment and the consummation of the transactions contemplated hereby. This Amendment has been duly and validly executed and delivered by such Party and
this Amendment constitutes a valid, legal and binding agreement of such Party (assuming that this Amendment has been duly and validly authorized, executed and delivered by each other Party), enforceable against such Party in accordance with its
terms, subject to the Bankruptcy and Equity Exception.

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. <u>General Provisions</u>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) This Amendment shall not constitute a waiver, amendment or modification of any provision of the Agreement not
expressly set forth in this Amendment. Except as specifically modified and amended by this Amendment, the Agreement shall remain unchanged and in full force and effect. References in the Agreement to "this Agreement",
"herein", "hereunder", "hereto", "hereof" and words of similar import shall refer to the Agreement as modified and amended by this Amendment. References to the date of the Agreement and references to
the "date hereof", "the date of this Agreement" or words of similar meaning in the Agreement shall continue to refer to May 6, 2025.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) Sections 9.1, 9.3, 9.4, 9.6, 9.8, 9.9, 9.10 and 9.14 through 9.17 of the Agreement shall apply to this
Amendment, *mutatis mutandis*.

[*Signature Page Follows*]

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IN WITNESS WHEREOF, each of the undersigned has caused this Amendment to be duly executed on its behalf as of the day and year first above written.

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| | |
|:---|:---|
| UNITIL CORPORATION | UNITIL CORPORATION |
| By: | /s/ Robert B. Hevert |
| Name: | Robert B. Hevert |
| Title: | President and Chief |
| Administrative Officer | Administrative Officer |
| AQUARION WATER AUTHORITY | AQUARION WATER AUTHORITY |
| By: | /s/ David Borowy |
| Name: | David Borowy |
| Title: | Authority Chair |
| SOUTH CENTRAL CONNECTICUT | SOUTH CENTRAL CONNECTICUT |
| REGIONAL WATER AUTHORITY | REGIONAL WATER AUTHORITY |
| By: | /s/ David Borowy |
| Name: | David Borowy |
| Title: | Authority Chair |

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*[Signature Page to Amendment No. 1 to Purchase and Sale Agreement]*