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<SEC-DOCUMENT>0000950134-06-017506.txt : 20060908
<SEC-HEADER>0000950134-06-017506.hdr.sgml : 20060908
<ACCEPTANCE-DATETIME>20060908155957
ACCESSION NUMBER:		0000950134-06-017506
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		5
CONFORMED PERIOD OF REPORT:	20060901
ITEM INFORMATION:		Entry into a Material Definitive Agreement
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20060908
DATE AS OF CHANGE:		20060908

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NATURAL GAS SERVICES GROUP INC
		CENTRAL INDEX KEY:			0001084991
		STANDARD INDUSTRIAL CLASSIFICATION:	OIL, GAS FIELD SERVICES, NBC [1389]
		IRS NUMBER:				752811855

	FILING VALUES:
		FORM TYPE:		8-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31398
		FILM NUMBER:		061081924

	BUSINESS ADDRESS:	
		STREET 1:		2911 SCR 1260
		CITY:			MIDLAND
		STATE:			TX
		ZIP:			79706
		BUSINESS PHONE:		9155633974

	MAIL ADDRESS:	
		STREET 1:		2911 SCR 1260
		CITY:			MIDLAND
		STATE:			TX
		ZIP:			79706
</SEC-HEADER>
<DOCUMENT>
<TYPE>8-K
<SEQUENCE>1
<FILENAME>d39563e8vk.htm
<DESCRIPTION>FORM 8-K
<TEXT>
<HTML>
<HEAD>
<TITLE>e8vk</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 1pt solid black; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="font-size: 14pt; margin-top: 12pt"><B>UNITED STATES SECURITIES AND EXCHANGE COMMISSION</B>
</DIV>

<DIV align="center" style="font-size: 12pt"><B>WASHINGTON, D.C. 20549</B>
</DIV>

<DIV align="center" style="font-size: 18pt; margin-top: 12pt"><B>FORM 8-K</B>
</DIV>


<DIV align="center" style="font-size: 12pt; margin-top: 12pt"><B>CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d)<BR>
OF THE SECURITIES EXCHANGE ACT OF 1934</B>
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><B>Date of Report (Date of earliest event reported): September&nbsp;1, 2006</B></DIV>

<DIV align="center" style="font-size: 24pt; margin-top: 12pt"><B>NATURAL GAS SERVICES GROUP, INC.</B>
</DIV>

<DIV align="center" style="font-size: 10pt">(Exact Name of Registrant as Specified in Its Charter)</DIV>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="30%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="30%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD align="center" valign="top">Colorado
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">1-31398
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">75-2811855</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">(State or other jurisdiction
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(Commission File
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(IRS Employer</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">of Incorporation or organization)
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">Number)
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">Identification No.)</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%">&nbsp;</TD>
    <TD width="10%">&nbsp;</TD>
    <TD width="25%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="30%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD colspan="2" align="center" valign="top">2911 South County Road 1260 Midland, Texas
</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">79706</TD>
</TR>
<TR valign="bottom">
    <TD colspan="2" align="center" valign="top">(Address of Principal Executive Offices)
</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(Zip Code)</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt">432-563-3974<BR>
(Registrant&#146;s telephone number, including area code)</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt">Not Applicable<BR>
(Former name or former address, if changed since last report)</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">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:
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><FONT face="Wingdings">&#111;</FONT> Written communications pursuant to Rule&nbsp;425 under the Securities Act
(17 CFR 230.425)
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><FONT face="Wingdings">&#111;</FONT> Soliciting material pursuant to Rule&nbsp;14a-12 under the Exchange Act (17
CFR 240.14a-12)
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><FONT face="Wingdings">&#111;</FONT> Pre-commencement communications pursuant to Rule&nbsp;14d-2(b) under the
Exchange Act (17 CFR 240.14d-2(b))
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><FONT face="Wingdings">&#111;</FONT> Pre-commencement communications pursuant to Rule&nbsp;13e-4(c) under the
Exchange Act (17 CFR 240.13e-4(c))
</DIV>


<DIV style="width: 100%; border-bottom: 1pt solid black; margin-top: 10pt; font-size: 1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>









<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="left" style="font-size: 10pt; margin-top: 12pt">Item&nbsp;1.01. Entry into a Material Definitive Agreement.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;On September&nbsp;1, 2006, Natural Gas Services Group, Inc., as borrower, and Western National
Bank, as lender, entered into modification agreements (collectively, the &#147;Modification
Agreements&#148;), modifying the following promissory notes (collectively, the &#147;Notes&#148;), each of which
evidence a loan facility made available to Natural Gas under the previously reported Sixth Amended
and Restated Loan Agreement dated January&nbsp;3, 2006 (the &#147;Loan Agreement&#148;), between Natural Gas and
Western National Bank:
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1)&nbsp;Revolving Line of Credit Promissory Note dated January&nbsp;3, 2006, in the original principal
amount of $10,000,000.00, as modified by a Modification Agreement dated effective as of March&nbsp;24,
2006, executed by Natural Gas in favor of Western National Bank (the &#147;Revolving Line of Credit
Promissory Note&#148;);
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2)&nbsp;Term Promissory Note dated January&nbsp;3, 2005, in the original principal amount of
$8,000,000.00, as modified by a Modification Agreement dated May&nbsp;1, 2005, and as further modified
by a Second Modification Agreement dated effective as of March&nbsp;24, 2006, executed by Natural Gas in
favor of Western National Bank (as so modified, the &#147;$8,000,000.00 Term Promissory Note&#148;);
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3)&nbsp;Multiple Advance Term Promissory Note dated March&nbsp;14, 2005, in the original principal
amount of $10,000,000.00, as modified by a Modification Agreement dated May&nbsp;1, 2005, and as further
modified by a Second Modification Agreement dated effective as of March&nbsp;24, 2006, executed by
Natural Gas in favor of Western National Bank (as so modified, the &#147;10,000,000.00 Multiple Advance
Term Promissory Note&#148;); and
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(4)&nbsp;Advancing Line of Credit Promissory Note dated November&nbsp;3, 2003, in the original principal
amount of $10,000,000.00, as modified by a Modification Agreement dated December&nbsp;15, 2004, a Second
Modification Agreement dated May&nbsp;1, 2005, and as further modified by a Third Modification Agreement
dated effective as of March&nbsp;24, 2006, executed by Natural Gas in favor of Western National Bank (as
so modified, the &#147;$10,000,000.00 Advancing Line of Credit Promissory Note&#148;).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Modification Agreements entered into by Natural Gas and Western National Bank included the
following:
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1)&nbsp;Second Modification Agreement dated effective as of August&nbsp;28, 2006, modifying the
Revolving Line of Credit Promissory Note;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2)&nbsp;Third Modification Agreement dated effective as of August&nbsp;28, 2006, modifying the
$8,000,000.00 Term Promissory Note;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3)&nbsp;Third Modification Agreement dated effective as of August&nbsp;28, 2006, modifying the
$10,000,000.00 Multiple Advance Term Promissory Note; and
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(4)&nbsp;Fourth Modification Agreement dated effective as of August&nbsp;28, 2006, modifying the
$10,000,000.00 Advancing Line of Credit Promissory Note.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Under the Modification Agreements, the annual rate at which each Note bears interest was
reduced from a variable rate equal to the &#147;prime rate&#148; as published in the Money Rates section of
The Wall Street Journal, to a fixed rate of seven and one-half percent (7.50%).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The remaining terms and provisions of the Loan Agreement and the Notes remain in full force
and effect.
</DIV>

<P align="center" style="font-size: 10pt"><!-- Folio -->2<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="left" style="font-size: 10pt; margin-top: 12pt">Item&nbsp;9.01 Financial Statements and Exhibits.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;Exhibits.
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="10%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="89%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" style="border-bottom: 1px solid #000000">Exhibit No.</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 1px solid #000000">Description</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">*10.1
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Second Modification Agreement dated effective as of
August&nbsp;28, 2006, by and between Natural Gas Services Group, Inc. and
Western National Bank.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">*10.2
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Third Modification Agreement dated effective as of
August&nbsp;28, 2006, by and between Natural Gas Services Group, Inc. and
Western National Bank.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">*10.3
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Third Modification Agreement dated effective as of
August&nbsp;28, 2006, by and between Natural Gas Services Group, Inc. and
Western National Bank.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">*10.4
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Fourth Modification Agreement dated effective as of
August&nbsp;28, 2006, by and between Natural Gas Services Group, Inc. and
Western National Bank.</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="3%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">*</TD>
    <TD>&nbsp;</TD>
    <TD>Filed herewith</TD>
</TR>

</TABLE>



<P align="center" style="font-size: 10pt"><!-- Folio -->3<!-- /Folio -->
</DIV>

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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center" style="font-size: 10pt; margin-top: 18pt">SIGNATURES
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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.
</DIV>

<TABLE width="100%" border="0" cellspacing="0" cellpadding="0" style="font-size: 10pt">
<TR>
    <TD width="48%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="15%">&nbsp;</TD>
</TR>
<TR>
    <TD valign="top" align="left">&nbsp;</TD>
    <TD colspan="3" align="left">NATURAL GAS SERVICES GROUP, INC.<BR>
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD valign="top">By:&nbsp;&nbsp;</TD>
    <TD colspan="2" style="border-bottom: 1px solid #000000" align="left">/s/ Stephen C. Taylor
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="2" align="left">Stephen C. Taylor, President and CEO&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="2" align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>
</TABLE>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Dated: September&nbsp;8, 2006

</DIV>


<P align="center" style="font-size: 10pt"><!-- Folio -->4<!-- /Folio -->
</DIV>

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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><U>EXHIBIT INDEX</U>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="10%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="89%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" style="border-bottom: 1px solid #000000">Exhibit No.</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 1px solid #000000">Description</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">*10.1
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Second Modification Agreement dated effective as of
August&nbsp;28, 2006, by and between Natural Gas Services Group, Inc. and
Western National Bank.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">*10.2
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Third Modification Agreement dated effective as of
August&nbsp;28, 2006, by and between Natural Gas Services Group, Inc. and
Western National Bank.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">*10.3
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Third Modification Agreement dated effective as of
August&nbsp;28, 2006, by and between Natural Gas Services Group, Inc. and
Western National Bank.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">*10.4
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Fourth Modification Agreement dated effective as of
August&nbsp;28, 2006, by and between Natural Gas Services Group, Inc. and
Western National Bank.</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="3%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">*</TD>
    <TD>&nbsp;</TD>
    <TD>Filed herewith</TD>
</TR>

</TABLE>




<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>

</BODY>
</HTML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-10.1
<SEQUENCE>2
<FILENAME>d39563exv10w1.htm
<DESCRIPTION>SECOND MODIFICATION AGREEMENT
<TEXT>
<HTML>
<HEAD>
<TITLE>exv10w1</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="right" style="font-size: 10pt; margin-top: 12pt">Exhibit&nbsp;10.1
</DIV>


<DIV align="right" style="font-size: 10pt; margin-top: 12pt">Revolving Line of Credit Note<BR>
dated January&nbsp;3, 2006
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><U>SECOND MODIFICATION AGREEMENT</U>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Second Modification Agreement (&#147;<U>Second Modification Agreement</U>&#148;) is effective as
of August&nbsp;28, 2006. The parties to the Second Modification Agreement are Natural Gas Services
Group, Inc. (&#147;<U>Borrower</U>&#148;) and Western National Bank (&#147;<U>Lender</U>&#148;).
</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>RECITALS</B>

</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;On January&nbsp;3, 2006, Borrower executed and delivered to Lender that certain Revolving Line of
Credit Promissory Note in the original principal sum of $10,000,000.00, bearing interest at the
rate stated therein, with a stated final maturity date of December&nbsp;1, 2006, as modified in
Modification Agreement dated March&nbsp;24, 2006 (the &#147;<U>Note</U>&#148;). The Note was made pursuant to
that certain Sixth Amended and Restated Loan Agreement dated January&nbsp;3, 2006 (the &#147;<U>Loan
Agreement</U>&#148;). All liens, security interests and assignments securing the Note are collectively
called the &#147;<U>Liens</U>&#148;. Terms defined in the Note or the Loan Agreement and not otherwise
defined herein shall have the same meanings here as in those documents.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;At Borrower&#146;s request, Borrower and Lender have agreed to enter into this Second Modification
Agreement to modify the interest provisions of the Note and to ratify the Liens.
</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>AGREEMENT</B>

</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;<B>Modification of Interest Provisions of the Note</B>. In lieu of the following provisions which
were contained in the first paragraph of the Note:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&#147;...at a rate per annum which shall from day to day be equal to the lesser of (a)&nbsp;a
rate per annum (the &#147;<U>Established Rate</U>&#148;) equal to the Prime Rate in effect
from day to day, or (b)&nbsp;the Highest Lawful Rate, in each case calculated on the
basis of actual days elapsed, but computed as if each calendar year consisted of 360
days.&#148;
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">such provisions of the Note are changed to read in their entirety as follows:
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&#147;...at a rate per annum which shall be equal to the lesser of (a)&nbsp;seven and one-half
percent (7.50%) (the &#147;<U>Established Rate</U>&#148;), or (b)&nbsp;the Highest Lawful Rate, in
each case calculated on the basis of actual days elapsed, but computed as if each
calendar year consisted of 360&nbsp;days.&#148;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;<B>Ratification of Liens</B>. Borrower and Lender further agree that all Liens securing the Note
shall continue and carry forward until the Note and all indebtedness evidenced thereby is paid in
full. Borrower further agrees that such liens are hereby ratified and affirmed as valid and
subsisting against the collateral described therein, and that this Second Modification Agreement
shall in no manner vitiate, affect or impair the Note or the Liens (except as expressly modified in
this Second Modification Agreement) and that such Liens shall not in any manner be waived,
released, altered or modified.
</DIV>

<P align="center" style="font-size: 10pt"><!-- Folio -->1<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.&nbsp;<B>Miscellaneous</B>.
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(a)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>As modified hereby, the provisions of the Note and the Liens shall continue in
full force and effect, and Borrower acknowledges and affirms its liability to Lender
thereunder. In the event of an inconsistency between this Second Modification
Agreement and the terms of the Note or of the Liens, this Second Modification Agreement
shall govern.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(b)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Borrower hereby agrees to pay all costs and expenses incurred by Lender in
connection with the execution and administration of this Second Modification Agreement.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(c)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Any default by Borrower in the performance of its obligations herein contained
shall constitute a default under the Note and the Liens and shall allow Lender to
exercise any or all of its remedies set forth in such Note and Liens or at law or in
equity.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(d)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Lender does not, by its execution of this Second Modification Agreement, waive
any rights it may have against any person not a party hereto.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(e)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>All terms, provisions, covenants, agreements, and conditions of the Note and
the Liens are unchanged, except as provided herein. Borrower agrees that this Second
Modification Agreement and all of the covenants and agreements contained herein shall
be binding upon Borrower and shall inure to the benefit of Lender and each of their
respective heirs, executors, legal representatives, successors, and permitted assigns.</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%"><B>THIS SECOND MODIFICATION AGREEMENT REPRESENTS THE FINAL AGREEMENT BETWEEN THE
PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR
SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS
BETWEEN THE PARTIES.</B>
</DIV>

<TABLE width="100%" border="0" cellspacing="0" cellpadding="0" style="font-size: 10pt">
<TR>
    <TD width="48%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="15%">&nbsp;</TD>
</TR>
<TR>
    <TD valign="top" align="left">&nbsp;</TD>
    <TD colspan="3" align="left"><u><B>Borrower</B></u><B>:<BR>
<BR>
Natural Gas Services Group, Inc.</B><BR>
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD valign="top">By:&nbsp;&nbsp;</TD>
    <TD colspan="2" style="border-bottom: 1px solid #000000" align="left">/s/ Stephen C. Taylor
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="2" align="left">Stephen C. Taylor, President&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="2" align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>
<TR>
    <TD valign="top" align="left">&nbsp;</TD>
    <TD colspan="3" align="left"><u><B>Lender</B></u><B>:<BR>
<BR>
Western National Bank</B><BR>
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD valign="top">By:&nbsp;&nbsp;</TD>
    <TD colspan="2" style="border-bottom: 1px solid #000000" align="left">
/s/ Scott A. Lovett
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="2" align="left">Scott A. Lovett, Executive Vice President&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="2" align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>
</TABLE>


<P align="center" style="font-size: 10pt"><!-- Folio -->2<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="19%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="80%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">STATE OF TEXAS
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">COUNTY OF MIDLAND
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This instrument was acknowledged before me on September&nbsp;1, 2006, by Stephen C. Taylor,
President of Natural Gas Services Group, Inc., a Colorado corporation, on behalf of said
corporation.
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="55%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">/s/ Lisa D. Taylor
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Notary Public, State of Texas</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="19%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="80%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">STATE OF TEXAS
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">COUNTY OF MIDLAND
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This instrument was acknowledged before me on September&nbsp;1, 2006, by Scott A. Lovett, Executive
Vice President of Western National Bank, a national banking association, on behalf of said
association.
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="55%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">/s/ Lisa D. Taylor
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Notary Public, State of Texas</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt"><!-- Folio -->3<!-- /Folio -->
</DIV>

</BODY>
</HTML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-10.2
<SEQUENCE>3
<FILENAME>d39563exv10w2.htm
<DESCRIPTION>THIRD MODIFICATION AGREEMENT
<TEXT>
<HTML>
<HEAD>
<TITLE>exv10w2</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="right" style="font-size: 10pt; margin-top: 12pt">Exhibit&nbsp;10.2
</DIV>


<DIV align="right" style="font-size: 10pt; margin-top: 12pt">$8,000,000.00 Term Note<BR>
dated January&nbsp;3, 2005
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 6pt"><U>THIRD MODIFICATION AGREEMENT</U>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Third Modification Agreement (&#147;<U>Third Modification Agreement</U>&#148;) is effective as of
August&nbsp;28, 2006. The parties to the Third Modification Agreement are Natural Gas Services Group,
Inc. (&#147;<U>Borrower</U>&#148;) and Western National Bank (&#147;<U>Lender</U>&#148;).
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>RECITALS</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;On January&nbsp;3, 2005, Borrower executed and delivered to Lender that certain Term Promissory
Note in the original principal sum of $8,000,000.00, bearing interest at the rate stated therein,
with a stated final maturity date of January&nbsp;1, 2012, as modified in Modification Agreement dated
May&nbsp;1, 2005, and further modified in Second Modification Agreement dated March&nbsp;24, 2006 (the
&#147;<U>Note</U>&#148;). The Note was made pursuant to that certain Third Amended and Restated Loan
Agreement dated January&nbsp;3, 2005, as amended and restated in that certain Fourth Amended and
Restated Loan Agreement dated March&nbsp;14, 2005, as modified in First Modification to Fourth Amended
and Restated Loan Agreement dated May&nbsp;1, 2005, and further amended and restated in Fifth Amended
and Restated Loan Agreement dated September&nbsp;26, 2005, and further amended and restated in Sixth
Amended and Restated Loan Agreement dated January&nbsp;3, 2006 (the &#147;<U>Loan Agreement</U>&#148;). All
liens, security interests and assignments securing the Note are collectively called the
&#147;<U>Liens</U>&#148;. Terms defined in the Note or the Loan Agreement and not otherwise defined herein
shall have the same meanings here as in those documents.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;At Borrower&#146;s request, Borrower and Lender have agreed to enter into this Third Modification
Agreement to modify the interest provisions of the Note and to ratify the Liens.
</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>AGREEMENT</B>

</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;<B>Modification of Interest Provisions of the Note</B>. In lieu of the following provisions which
were contained in the first paragraph of the Note:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&#147;...at a rate per annum which shall from day to day be equal to the lesser of (a)&nbsp;a
rate per annum (the &#147;<U>Established Rate</U>&#148;) equal to the Prime Rate in effect
from day to day, or (b)&nbsp;the Highest Lawful Rate, in each case calculated on the
basis of actual days elapsed, but computed as if each calendar year consisted of 360
days.&#148;
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">such provisions of the Note are changed to read in their entirety as follows:
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&#147;...at a rate per annum which shall be equal to the lesser of (a)&nbsp;seven and one-half
percent (7.50%) (the &#147;<U>Established Rate</U>&#148;), or (b)&nbsp;the Highest Lawful Rate, in
each case calculated on the basis of actual days elapsed, but computed as if each
calendar year consisted of 360&nbsp;days.&#148;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;<B>Ratification of Liens</B>. Borrower and Lender further agree that all Liens securing the Note
shall continue and carry forward until the Note and all indebtedness evidenced thereby is paid in
full. Borrower further agrees that such liens are hereby ratified and affirmed as valid and
subsisting against the collateral described therein, and that this
</DIV>

<P align="center" style="font-size: 10pt"><!-- Folio -->1<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">



<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Third Modification Agreement shall in no manner vitiate, affect or impair the Note or the Liens
(except as expressly modified in this Third Modification Agreement) and that such Liens shall not
in any manner be waived, released, altered or modified.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.&nbsp;<B>Miscellaneous</B>.
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(a)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>As modified hereby, the provisions of the Note and the Liens shall continue in
full force and effect, and Borrower acknowledges and affirms its liability to Lender
thereunder. In the event of an inconsistency between this Third Modification Agreement
and the terms of the Note or of the Liens, this Third Modification Agreement shall
govern.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(b)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Borrower hereby agrees to pay all costs and expenses incurred by Lender in
connection with the execution and administration of this Third Modification Agreement.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(c)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Any default by Borrower in the performance of its obligations herein contained
shall constitute a default under the Note and the Liens and shall allow Lender to
exercise any or all of its remedies set forth in such Note and Liens or at law or in
equity.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(d)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Lender does not, by its execution of this Third Modification Agreement, waive
any rights it may have against any person not a party hereto.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(e)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>All terms, provisions, covenants, agreements, and conditions of the Note and
the Liens are unchanged, except as provided herein. Borrower agrees that this Third
Modification Agreement and all of the covenants and agreements contained herein shall
be binding upon Borrower and shall inure to the benefit of Lender and each of their
respective heirs, executors, legal representatives, successors, and permitted assigns.</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%"><B>THIS THIRD MODIFICATION AGREEMENT REPRESENTS THE FINAL AGREEMENT BETWEEN THE PARTIES
AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT
ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE
PARTIES.</B>
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="48%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="26%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="18%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><U><B>Borrower</B></U><B>:</B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><B>Natural Gas Services Group, Inc.</B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ Stephen C. Taylor</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Stephen C. Taylor, President</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><U><B>Lender:</B></U></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><B>Western National Bank</B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ Scott A. Lovett</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top"><FONT style="white-space: nowrap">Scott A. Lovett, Executive Vice President</FONT></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt"><!-- Folio -->2<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="63%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">STATE OF TEXAS
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">COUNTY OF MIDLAND
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This instrument was acknowledged before me on September&nbsp;1, 2006, by Stephen C. Taylor,
President of Natural Gas Services Group, Inc., a Colorado corporation, on behalf of said
corporation.
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="60%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="26%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="12%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">/s/ Lisa D. Taylor
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
<DIV align="left">Notary Public, State of Texas</DIV>
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="63%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">STATE OF TEXAS
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">COUNTY OF MIDLAND
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This instrument was acknowledged before me on September&nbsp;1, 2006, by Scott A. Lovett, Executive
Vice President of Western National Bank, a national banking association, on behalf of said
association.
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="60%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="26%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="12%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">/s/ Lisa D. Taylor
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
<DIV align="left">Notary Public, State of Texas</DIV>
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt"><!-- Folio -->3<!-- /Folio -->
</DIV>

</BODY>
</HTML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-10.3
<SEQUENCE>4
<FILENAME>d39563exv10w3.htm
<DESCRIPTION>THIRD MODIFICATION AGREEMENT
<TEXT>
<HTML>
<HEAD>
<TITLE>exv10w3</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="right" style="font-size: 10pt; margin-top: 12pt">Exhibit&nbsp;10.3
</DIV>


<DIV align="right" style="font-size: 10pt; margin-top: 12pt">$10,000,000.00 Multiple Advance Term Note<BR>
dated March&nbsp;14, 2005
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><U>THIRD MODIFICATION AGREEMENT</U>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Third Modification Agreement (&#147;<U>Third Modification Agreement</U>&#148;) is effective as of
August&nbsp;28, 2006. The parties to the Third Modification Agreement are Natural Gas Services Group,
Inc. (&#147;<U>Borrower</U>&#148;) and Western National Bank (&#147;<U>Lender</U>&#148;).
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>RECITALS</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;On March&nbsp;14, 2005, Borrower executed and delivered to Lender that certain Multiple Advance
Term Promissory Note in the original principal sum of $10,000,000.00, bearing interest at the rate
stated therein, with a stated final maturity date of April&nbsp;1, 2011, as modified in Modification
Agreement dated May&nbsp;1, 2005, and further modified in Second Modification Agreement dated March&nbsp;24,
2006 (the &#147;<U>Note</U>&#148;). The Note was made pursuant to that certain Fourth Amended and Restated
Loan Agreement dated March&nbsp;14, 2005, as modified in that certain First Modification to Fourth
Amended and Restated Loan Agreement dated May&nbsp;1, 2005; and further amended and restated in that
certain Fifth Amended and Restated Loan Agreement dated September&nbsp;26, 2005; and further amended and
restated in that certain Sixth amended and Restated Loan Agreement dated January&nbsp;3, 2006 (the
&#147;<U>Loan Agreement</U>&#148;). All liens, security interests and assignments securing the Note are
collectively called the &#147;<U>Liens</U>&#148;. Terms defined in the Note or the Loan Agreement and not
otherwise defined herein shall have the same meanings here as in those documents.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;At Borrower&#146;s request, Borrower and Lender have agreed to enter into this Third Modification
Agreement to modify the interest provisions of the Note and to ratify the Liens.
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>AGREEMENT</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">1. <B>Modification of Interest Provisions of the Note</B>. In lieu of the following provisions which were
contained in the first paragraph of the Note:
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 3%">&#147;...at a rate per annum which shall from day to day be equal to the lesser of (a)&nbsp;a
rate per annum (the &#147;<U>Established Rate</U>&#148;) equal to the Prime Rate in effect
from day to day, or (b)&nbsp;the Highest Lawful Rate, in each case calculated on the
basis of actual days elapsed, but computed as if each calendar year consisted of 360
days.&#148;
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">such provisions of the Note are changed to read in their entirety as follows:
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 3%">&#147;...at a rate per annum which shall be equal to the lesser of (a)&nbsp;seven and one-half
percent (7.50%) (the &#147;<U>Established Rate</U>&#148;), or (b)&nbsp;the Highest Lawful Rate, in
each case calculated on the basis of actual days elapsed, but computed as if each
calendar year consisted of 360&nbsp;days.&#148;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt; text-indent: 3%">2.&nbsp;<B>Ratification of Liens</B>. Borrower and Lender further agree that all Liens securing the Note
shall continue and carry forward until the Note and all indebtedness evidenced thereby is paid in
full. Borrower further agrees that such liens are hereby ratified and affirmed as valid and
subsisting against the collateral described therein, and that this Third Modification Agreement
shall in no manner vitiate, affect or impair the Note or the Liens
</DIV>

<P align="center" style="font-size: 10pt"><!-- Folio -->1<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(except as expressly modified in this Third Modification Agreement) and that such Liens shall not
in any manner be waived, released, altered or modified.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">3.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD><B>Miscellaneous</B>.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">(a)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>As modified hereby, the provisions of the Note and the Liens shall continue in
full force and effect, and Borrower acknowledges and affirms its liability to Lender
thereunder. In the event of an inconsistency between this Third Modification Agreement
and the terms of the Note or of the Liens, this Third Modification Agreement shall
govern.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">(b)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Borrower hereby agrees to pay all costs and expenses incurred by Lender in
connection with the execution and administration of this Third Modification Agreement.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">(c)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Any default by Borrower in the performance of its obligations herein contained
shall constitute a default under the Note and the Liens and shall allow Lender to
exercise any or all of its remedies set forth in such Note and Liens or at law or in
equity.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">(d)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Lender does not, by its execution of this Third Modification Agreement, waive
any rights it may have against any person not a party hereto.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">(e)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>All terms, provisions, covenants, agreements, and conditions of the Note and
the Liens are unchanged, except as provided herein. Borrower agrees that this Third
Modification Agreement and all of the covenants and agreements contained herein shall
be binding upon Borrower and shall inure to the benefit of Lender and each of their
respective heirs, executors, legal representatives, successors, and permitted assigns.</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%"><B>THIS THIRD MODIFICATION AGREEMENT REPRESENTS THE FINAL AGREEMENT BETWEEN THE PARTIES
AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT
ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE
PARTIES.</B>
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="48%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="38%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="11%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="bottom" align="left"><B><U>Borrower:</U></B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="bottom" align="left"><B>Natural Gas Services Group, Inc.</B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">/s/ Stephen C. Taylor</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">Stephen C. Taylor, President</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="bottom" align="left"><B><U>Lender:</U></B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="bottom" align="left"><B>Western National Bank</B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">/s/ Scott A. Lovett</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="bottom">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">Scott A. Lovett, Executive Vice President</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="bottom">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt"><!-- Folio -->2<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="74%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">STATE OF TEXAS
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">COUNTY OF MIDLAND
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This instrument was acknowledged before me on September&nbsp;1, 2006, by Stephen C. Taylor,
President of Natural Gas Services Group, Inc., a Colorado corporation, on behalf of said
corporation.
</DIV>

<TABLE width="100%" border="0" cellspacing="0" cellpadding="0" style="font-size: 10pt">
<TR>
    <TD width="48%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="15%">&nbsp;</TD>
</TR>
<TR>
    <TD valign="top" align="left">&nbsp;</TD>
    <TD colspan="3" align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD colspan="3" style="border-bottom: 1px solid #000000" align="center">/s/ Lisa D. Taylor
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD colspan="3" align="left">Notary Public, State of Texas&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD colspan="3" align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>
</TABLE>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="74%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">STATE OF TEXAS
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">COUNTY OF MIDLAND
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This instrument was acknowledged before me on September&nbsp;1, 2006, by Scott A. Lovett, Executive
Vice President of Western National Bank, a national banking association, on behalf of said
association.
</DIV>

<TABLE width="100%" border="0" cellspacing="0" cellpadding="0" style="font-size: 10pt">
<TR>
    <TD width="48%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="15%">&nbsp;</TD>
</TR>
<TR>
    <TD valign="top" align="left">&nbsp;</TD>
    <TD colspan="3" align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD colspan="3" style="border-bottom: 1px solid #000000" align="center">/s/ Lisa D. Taylor
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD colspan="3" align="left">Notary Public, State of Texas&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD colspan="3" align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>
</TABLE>


<P align="center" style="font-size: 10pt"><!-- Folio -->3<!-- /Folio -->
</DIV>


</BODY>
</HTML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-10.4
<SEQUENCE>5
<FILENAME>d39563exv10w4.htm
<DESCRIPTION>FOURTH MODIFICATION AGREEMENT
<TEXT>
<HTML>
<HEAD>
<TITLE>exv10w4</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
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<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="right" style="font-size: 10pt; margin-top: 12pt">Exhibit&nbsp;10.4
</DIV>


<DIV align="right" style="font-size: 10pt; margin-top: 12pt">$10,000,000 Advance Note<BR>
November&nbsp;3, 2003
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><U>FOURTH MODIFICATION AGREEMENT</U>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Fourth Modification Agreement (&#147;<U>Fourth Modification Agreement</U>&#148;) is effective as
of August&nbsp;28, 2006. The parties to the Fourth Modification Agreement are Natural Gas Services
Group, Inc. (&#147;<U>Borrower</U>&#148;) and Western National Bank (&#147;<U>Lender</U>&#148;).
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>RECITALS</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;On November&nbsp;3, 2003, Borrower executed and delivered to Lender that certain Advancing Line of
Credit Promissory Note in the original principal sum of $10,000,000.00, bearing interest at the
rate stated therein, with a stated final maturity date of November&nbsp;15, 2009, as modified in
Modification Agreement dated December&nbsp;15, 2004, and further modified in Second Modification
Agreement dated May&nbsp;1, 2005, and further modified in Third Modification Agreement dated March&nbsp;24,
2006 (the &#147;<U>Note</U>&#148;). The Note was made pursuant to that certain Second Amended and Restated
Loan Agreement dated November&nbsp;3, 2003, as amended and restated in that certain Third Amended and
Restated Loan Agreement dated January&nbsp;3, 2005, and further amended and restated in that certain
Fourth Amended and Restated Loan Agreement dated March&nbsp;14, 2005, as modified in that certain First
Modification to Fourth Amended and Restated Loan Agreement dated May&nbsp;1, 2005; and further amended
and restated in that certain Fifth Amended and Restated Loan Agreement dated September&nbsp;26, 2005;
and further amended and restated in that certain Sixth Amended and Restated Loan Agreement dated
January&nbsp;3, 2006 (the &#147;<U>Loan Agreement</U>&#148;). All liens, security interests and assignments
securing the Note are collectively called the &#147;<U>Liens</U>&#148;. Terms defined in the Note or the
Loan Agreement and not otherwise defined herein shall have the same meanings here as in those
documents.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;At Borrower&#146;s request, Borrower and Lender have now agreed to enter into this Fourth
Modification Agreement to modify the interest provisions of the Note and to ratify the Liens.
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>AGREEMENT</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;<B>Modification of Interest Provision of the Note</B>. In lieu of the following provision which
was contained in the Note:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&#147;...at a rate per annum which shall from day to day be equal to the lesser of (a)&nbsp;a
rate per annum (the &#147;<U>Established Rate</U>&#148;) equal to the Prime Rate in effect
from day to day, or (b)&nbsp;the Highest Lawful Rate, in each case calculated on the
basis of actual days elapsed, but computed as if each calendar year consisted of 360
days.&#148;
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">such provision of the Note is changed to read in its entirety as follows:
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&#147;...at a rate per annum equal to the lesser of (a)&nbsp;seven and one-half percent
(7.50%) (the &#147;<U>Established Rate</U>&#148;), or (b)&nbsp;the Highest Lawful Rate, in each
case calculated on the basis of actual days elapsed, but computed as if each
calendar year consisted of 360&nbsp;days.&#148;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;<B>Ratification of Liens. </B>Borrower and Lender further agree that all Liens securing the Note
shall continue and carry forward until the Note and all indebtedness
</DIV>

<P align="center" style="font-size: 10pt"><!-- Folio -->1<!-- /Folio -->
</DIV>

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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">evidenced thereby is paid in full. Borrower further agrees that such Liens are hereby ratified and
affirmed as valid and subsisting against the collateral described therein, and that this Fourth
Modification Agreement shall in no manner vitiate, affect or impair the Note or the Liens (except
as expressly modified in this Fourth Modification Agreement) and that such Liens shall not in any
manner be waived, released, altered or modified.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">3.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD><B>Miscellaneous</B>.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(a)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>As modified hereby, the provisions of the Note and the Liens shall continue in
full force and effect, and Borrower acknowledges and affirms its liability to Lender
thereunder. In the event of an inconsistency between this Fourth Modification
Agreement and the terms of the Note or of the Liens, this Fourth Modification Agreement
shall govern.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(b)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Borrower hereby agrees to pay all costs and expenses incurred by Lender in
connection with the execution and administration of this Fourth Modification Agreement.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(c)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Any default by Borrower in the performance of its obligations herein contained
shall constitute a default under the Note and the Liens and shall allow Lender to
exercise any or all of its remedies set forth in such Note and Liens or at law or in
equity.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(d)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Lender does not, by its execution of this Fourth Modification Agreement, waive
any rights it may have against any person not a party hereto.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="4%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(e)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>All terms, provisions, covenants, agreements, and conditions of the Note and
the Liens are unchanged, except as provided herein. Borrower agrees that this Fourth
Modification Agreement and all of the covenants and agreements contained herein shall
be binding upon Borrower and shall inure to the benefit of Lender and each of their
respective heirs, executors, legal representatives, successors, and permitted assigns.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left"><B>&nbsp;</B></TD>
    <TD width="1%"><B>&nbsp;</B></TD>
    <TD><B>THIS FOURTH MODIFICATION AGREEMENT REPRESENTS THE FINAL AGREEMENT BETWEEN THE
PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR
SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS
BETWEEN THE PARTIES.</B></TD>
</TR>

</TABLE>
</DIV>
<DIV align="left">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="90%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="48%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="47%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><u><B>Borrower</B></u>:</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><B>Natural Gas Services Group, Inc.</B></TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ Stephen C. Taylor</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Stephen C. Taylor, President</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><u><B>Lender</B></u><B>:</B></TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><B>Western National Bank</B></TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ Scott A. Lovett</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Scott A. Lovett, Executive Vice President</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt"><!-- Folio -->2<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="26%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="68%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">STATE OF TEXAS
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">COUNTY OF MIDLAND
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This instrument was acknowledged before me on September&nbsp;1, 2006, by Stephen C. Taylor,
President of Natural Gas Services Group, Inc., a Colorado corporation, on behalf of said
corporation.
</DIV>
<DIV align="left">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="90%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="48%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="46%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">/s/ Lisa D. Taylor</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Notary Public, State of Texas</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="26%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="68%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">STATE OF TEXAS
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">COUNTY OF MIDLAND
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&#167;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This instrument was acknowledged before me on September&nbsp;1, 2006, by Scott A. Lovett, Executive
Vice President of Western National Bank, a national banking association, on behalf of said
association.
</DIV>
<DIV align="left">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="90%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="48%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="46%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">/s/ Lisa D. Taylor</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Notary Public, State of Texas</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



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