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

October 29, 2016

Date of Report (Date of earliest event reported)

ATMOS ENERGY CORPORATION

(Exact Name of Registrant as Specified in its Charter)

(972) 934-9227

(Registrant’s Telephone Number, Including Area Code)

Not Applicable

(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:

On October 29, 2016, Atmos Energy Holdings, Inc. (“Holdings”), a wholly-owned subsidiary of Atmos Energy Corporation (“Atmos Energy”), entered into an agreement (the “Agreement”) to sell all of the membership interests in Atmos Energy Marketing, LLC (“Marketing”), to CenterPoint Energy Services, Inc. (“CP Energy Services”), an affiliate of CenterPoint Energy, Inc. (“CenterPoint”), for a purchase price of $40 million plus working capital at the closing. Working capital at the closing is expected to be approximately $80 million. The Agreement contains the usual terms and conditions customary for transactions of this type, including adjustments to the working capital at closing and indemnification by Holdings related to the business of Marketing prior to closing and breaches of representations and warranties regarding the business conducted by Marketing. The closing of the transaction is subject to the satisfaction of customary conditions including the receipt of applicable regulatory approvals. Neither Atmos Energy nor any of its affiliates, including Holdings or Marketing, have had a material relationship with CenterPoint or any of its affiliates, including CP Energy Services, other than in respect of the Agreement.

The foregoing description of the Agreement does not purport to be complete and is qualified in its entirety by reference to the Agreement, a copy of which is attached as Exhibit 2.1 hereto and incorporated into this Item 1.01 by reference. The Agreement is included as an exhibit to this Form 8-K to provide investors and security holders with information regarding its terms. It is not intended to provide any other factual or financial information about Atmos Energy, Marketing, CenterPoint, the other parties to the Agreement or any of their respective subsidiaries and affiliates. The representations, warranties and covenants contained in the Agreement were made only for purposes of that agreement and as of specific dates; were solely for the benefit of the parties to the Agreement; may be subject to limitations agreed upon by the parties, including being qualified by confidential disclosures made for the purposes of allocating contractual risk between the parties thereto instead of establishing these matters as facts; and may be subject to standards of materiality applicable to the contracting parties that differ from those applicable to investors. Investors should not rely on the representations, warranties and covenants or any description thereof as characterizations of the actual state of facts or condition of Atmos Energy, Marketing, CenterPoint, the other parties to the Agreement or any of their respective subsidiaries and affiliates. Moreover, information concerning the subject matter of the representations, warranties and covenants may change after the date of the Agreement, which subsequent information may or may not be fully reflected in public disclosures by Atmos Energy or CenterPoint.

Cautionary Statement for the Purposes of the Safe Harbor under the Private Securities Litigation Reform Act of 1995

The statements contained in this Current Report on Form 8-K may contain “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. All statements other than statements of historical fact included in this Report are forward-looking statements made in good faith by us

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and are intended to qualify for the safe harbor from liability established by the Private Securities Litigation Reform Act of 1995. When used in this Report, the word “expect” or similar words are intended to identify forward-looking statements. Such forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied in the statements relating to our strategy, operations, markets, services and other factors. Accordingly, while we believe these forward-looking statements to be reasonable, there can be no assurance that they will approximate actual experience or that the expectations derived from them will be realized. Further, we undertake no obligation to update or revise any of our forward-looking statements whether as a result of new information, future events or otherwise.

On October 31, 2016, Atmos Energy announced in a news release that Holdings had entered into the Agreement described above under Item 1.01. A copy of the news release is furnished as Exhibit 99.1. The information furnished in this Item 7.01 and in Exhibit 99.1 shall not be deemed to be “filed” for purposes of Section 18 of the Exchange Act or otherwise subject to the liabilities of that section, nor shall such information be deemed to be incorporated by reference into any of the Company’s filings under the Securities Act of 1933 or the Securities Exchange Act of 1934.

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SIGNATURE

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.

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INDEX TO EXHIBITS

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