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 1934

Date of Report (Date of earliest event reported): May 6, 2011

UNITIL CORPORATION

(Exact name of registrant as specified in its charter)

New Hampshire	1-8858	02-0381573
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer 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))

Item 7.01 Regulation FD Disclosure

On May 6, 2011, Unitil Corporation (“Unitil” or “Registrant”) issued a press release announcing that its natural gas distribution utility, Northern Utilities, Inc., filed two separate rate cases requesting approval to change its natural gas distribution base rates with the New Hampshire Public Utilities Commission and the Maine Public Utilities Commission. A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Item 9.01 Financial Statements and Exhibits

(d) Exhibits

Number	Exhibit
99.1	May 6, 2011 press release announcing the filing of rate cases for Northern Utilities, Inc.

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/ Mark H. Collin
	Mark H. Collin
	Senior Vice President, Chief Financial Officer and Treasurer

Date: May 6, 2011

EXHIBIT INDEX

Number	Exhibit
99.1	May 6, 2011 press release announcing the filing of rate cases for Northern Utilities, Inc.

EX-99.1

Exhibit 99.1

FOR IMMEDIATE RELEASE PAGE 1 OF 2

UNITIL FILES FOR CHANGES IN NATURAL GAS DISTRIBUTION RATES

MAY 6, 2011 Hampton, New Hampshire – Unitil Corporation (NYSE:UTL) (www.unitil.com) announced today that its local natural gas distribution utility recently filed two separate rate cases requesting approval to change its natural gas distribution base rates with the New Hampshire Public Utilities Commission and the Maine Public Utilities Commission.

The filings represent the first rate case in approximately 10 years for Unitil’s New Hampshire gas distribution operations and 28 years for its Maine gas distribution operations. In New Hampshire, the Company has requested an increase of $5.2 million in gas distribution base revenue, which represents an increase of approximately 8.1% over current operating revenue. In Maine, the Company has requested an increase of $10.1 million in gas distribution base revenue or an increase of approximately 16.7% over current operating revenue. Both filings include a proposed capital cost recovery tracking mechanism to recover the future costs associated with Unitil’s cast iron and bare steel replacement programs. The rate case filings are subject to regulatory review and approval with final rate orders expected in the first half of 2012. Unitil has also requested temporary rates in both states. If approved, the temporary rate requests would go into effect in the third quarter of 2011, subject to refund or adjustment.

“Unitil has made significant operating improvements and investments since acquiring its New Hampshire and Maine local gas distribution operations in December of 2008,” Unitil’s Senior Vice President, George Gantz, said. “These rate cases will provide an opportunity to bring revenues in line with current operating expenses and rate base. This will allow Unitil to continue its capital-intensive cast iron and bare steel replacement programs in both states, which are designed to maintain a safe and reliable natural gas distribution system and increase the availability of natural gas as a clean and cost-effective energy choice for our customers.”

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6 Liberty Lane West

Hampton, New Hampshire 03842

www.unitil.com

Ph: 603-772-0775 Fax: 603-773-6605

PAGE 2 OF 2

About Unitil Corporation

Unitil Corporation provides for the necessities of life, safely and reliably delivering natural gas and electricity throughout northern New England. We are committed to the communities we serve and to developing people, business practices, and technologies that lead to dependable, more efficient energy. Unitil is a public utility holding company with affiliates that include Unitil Energy Systems, Inc., Fitchburg Gas and Electric Light Company, Northern Utilities, Inc., and Granite State Gas Transmission, Inc. Together; Unitil Corporation’s operating utilities serve approximately 100,900 electric customers and 70,800, natural gas customers. Other subsidiaries include Unitil Service Corp. and Usource, a non-regulated business segment. For more information about our people, technologies, and community involvement please visit www.unitil.com.

For more information please contact:

David Chong – Investor Relations

Phone: 603-773-6499

Email: chong@unitil.com

Alec O’Meara – Media Relations

Phone: 603-773-6404

Email: omeara@unitil.com