Exhibit 10.1

AMENDMENT NO. ONE TO THE

ATMOS ENERGY CORPORATION

CHANGE IN CONTROL SEVERANCE AGREEMENT

TIER I

WHEREAS, on                     ,             , ATMOS ENERGY CORPORATION, a
Texas and Virginia corporation (the “Company”) and
                                         (“Executive”) entered into the Atmos
Energy Corporation Change in Control Severance Agreement, Tier I (the
“Agreement”), whereby the Company will provide certain benefits to Executive in
the event of a Change in Control of the Company; and

WHEREAS, the Company’s Board of Directors has approved the adoption of
amendments to each previously executed Change in Control Severance Agreement to
provide certain additional benefits to each covered executive in the event of a
Change in Control; and

WHEREAS, pursuant to Section 7 of the Agreement, the Company desires to amend
the Agreement in order to provide such additional benefits to Executive.

NOW, THEREFORE, the Company does hereby amend the Agreement, effective as of the
day and year hereinafter set forth, as follows:

1. Section 4.1 is amended, effective as of January 1, 2006, by striking
paragraph (b) and substituting in lieu thereof the following paragraph (b):

(b) In addition, Company shall pay to Executive in one lump sum not later than
the tenth (10th) day following the Date of Termination, an amount equal to the
total of (a) an amount that is actuarially equivalent to an additional three
(3) years of annual age and service credits payable to Executive under the
Company’s Pension Account Plan and (b) an amount that is actuarially equivalent
to an additional three (3) years of Company matching contributions payable to
Executive under the Company’s Retirement Savings Plan and Trust;

2. Section 4.1 is amended, effective as of January 1, 2006, by adding the
following new paragraph (c):

(c) The Company shall also continue to provide Executive with all (i) medical,
dental, vision, accident, and other health benefits, (ii) life insurance
benefits, and (iii) disability benefits (collectively, “health and welfare
benefits”), all of which are equal to or economically equivalent to the benefits
in effect for Executive at the time of the Change in Control, and the Company
shall provide such benefits at the same cost to Executive as the cost, if any,
charged to Executive for those benefits prior to the Date of Termination. The
Company may either provide the foregoing health and welfare benefits for

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the period from the Date of Termination until three (3) years from the Date of
Termination, or in its sole discretion, the Company may instead pay to Executive
no later than the tenth (10th) day following the Date of Termination, a lump sum
in an amount actuarially equivalent to the total value of such health and
welfare benefits continuation coverage.

3. All capitalized terms that are not otherwise defined herein shall have the
meanings subscribed to them in the Agreement.

IN WITNESS WHEREOF, the Company has caused this AMENDMENT NO. ONE TO THE ATMOS
ENERGY CORPORATION CHANGE IN CONTROL SEVERANCE AGREEMENT, TIER I, to be executed
in its name and on its behalf this          day of                         ,
2006, effective as of the dates provided herein.

 

ATMOS ENERGY CORPORATION By:  

 

  Robert W. Best   Chairman, President and Chief Executive Officer

Consented to and acknowledged by:

 

EXECUTIVE

 

[Name of Executive]

Date:                                          

 

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