Exhibit 10.6  CONFORMED COPY  CATERPILLAR INC., as Back-up Manager  UCO COMPRESSION 2005 LLC, as Issuer,  and  UNIVERSAL COMPRESSION, INC., as Manager   Dated as of October 28, 2005  ALL RIGHT, TITLE AND INTEREST IN
AND TO THIS AGREEMENT ON THE PART OF UCO COMPRESSION 2005 LLC HAS BEEN
ASSIGNED TO AND IS SUBJECT TO A SECURITY INTEREST IN FAVOR OF WELLS FARGO BANK,
NATIONAL ASSOCIATION, AS INDENTURE TRUSTEE, UNDER AN INDENTURE, DATED AS OF OCTOBER 28,
2005, FOR THE BENEFIT OF THE PERSONS REFERRED TO THEREIN.


BACK-UP
MANAGEMENT AGREEMENT  THIS BACK-UP MANAGEMENT AGREEMENT, dated as
of October 28, 2005 (as amended, supplemented or otherwise modified from
time to time in accordance with the terms hereof, this Agreement), is entered into by and
among CATERPILLAR INC., a corporation organized under the laws of the state of
Delaware (the Back-up Manager
or Caterpillar), UCO
COMPRESSION 2005 LLC, a limited liability company formed under the laws of the
state of Delaware (the Issuer),
and UNIVERSAL COMPRESSION, INC., a corporation organized under the laws of
the State of Texas (the Manager
or UCI).  RECITALS  WHEREAS, the Issuer is the owner of the Owner
Compressors; and  WHEREAS, the Issuer and the Manager have
entered into the Management Agreement, dated as of October 28, 2005 (as
amended, supplemented or otherwise modified from time to time in accordance
with its terms, the Management Agreement),
a copy of which is attached hereto as Exhibit A,
pursuant to which the Manager agreed, inter
alia, to operate and contract or sub-contract the Owner Compressors
in a manner consistent with any Other UCI Compressors; and  WHEREAS, the Back-up Manager desires toserve as a back-up
manager with respect to the Owner Compressors; and  WHEREAS, the Issuer desires to engage the
Back-up Manager to act as back-up manager with respect to the Owner
Compressors; and  NOW, THEREFORE, in consideration of the
premises and
mutual representations, warranties, covenants and agreements contained herein,
the receipt and adequacy of which are hereby acknowledged, and intending to be
legally bound, the parties hereto hereby agree as follows:  ARTICLE I  DEFINITIONS  Capitalized terms used in this Agreement not
otherwise defined herein shall have the meaning assigned to such terms in
Appendix A to the Indenture, dated as of October 28, 2005 (as amended,
supplemented or otherwise modified from time to time in accordance with its
terms, the Indenture),
between the Issuer and Wells
Fargo Bank, National Association, as indenture trustee (together with its
successors and assigns, the Indenture
Trustee), as such Appendix A may be amended, supplemented
or otherwise modified from time to time in accordance with the provisions of
the Indenture, and the rules of usage set forth in such Appendix A shall
apply to this Agreement, providedthat
any amendment to the Indenture, Appendix A thereto or any other Related
Document (other than as set forth below) shall not be binding on the Back-up
Manager to the extent such amendment would serve to expand the Back-up Managers
obligations or liabilities hereunder or thereunder or modify any of the rights
of the Back-up Manager hereunder or thereunder, including without limitation,
its rights to fees, without the prior written consent of the Back-up Manager; provided, however, notwithstanding anything contained herein
to the contrary, the parties shall not amend the Management Agreement or terms
in Appendix A (to the extent any terms are used in the Management Agreement and
such amendment would result in an adverse effect on the Back-up Manager)
without obtaining the prior written consent of the Back-up Manager; otherwise,
terms defined herein shall have the following meanings, and the definitions of
such terms shall be equally applicable to the singular and plural forms of such
terms:  1


Back-up
Manager Feemeans an amount equal to the amount set forth
in that separate fee letter agreement dated as of even date herewith by and
among the Manager, the Back-up Manager and the Issuer, as it may be
amended, modified or supplemented from time to time with the written consent of
the Requisite Global Majority.  Back-up Manager
Indemnified Party shall have the meaning set forth in Section 6.1 hereof.  Back-up Manager
Termination Notice shall have the meaning set forth in Section 4.1 hereof.  Claimshall
have the meaning set forth in Section 6.1
hereof.  Indemnified Party
shall have the meaning set forth in Section 6.2
hereof.  Management
Replacement Date shall mean the earlier of (a) ninety (90)
days after delivery and receipt of a Manager Termination Notice specifying a
Manager Default; and (b) the date which the Back-up Manager assumes in
writing all of the duties of the Manager under the Management Agreement except
as modified as set forth in Exhibit B
to this Agreement.  Schedule A
shall mean, with respect to any Owner Compressor, the respective Schedule A
attached to the form of master equipment agreement relating to providing contract
compression services for such Owner Compressors.  Status Reportshall
have the meaning set forth in Section 3.3(c)hereof.  Systems Data shall have the meaning set
forth in Section 2.2(b)hereof.  Transition Planshall
have the meaning set forth in Section 2.2(a)hereof.  ARTICLE II  APPOINTMENT OF BACK-UP MANAGER  SECTION 2.1The Issuer hereby appoints Caterpillar as the
initial Back-up Manager, and the Back-up Manager, in executing this Agreement,
hereby accepts such appointment on the terms and conditions set forth in this
Agreement. Other than the duties specifically set forth in this Agreement, the
Back-up Manager shall have no obligations hereunder, including, without
limitation, to supervise, verify, monitor or administer the performance of the
Manager or the Issuer. The Back-up Manager shall have no liability for any
actions taken or omitted by the Manager or by the Issuer. The duties and
obligations of the Back-up Manager shall be determined solely by the express
provisions of this Agreement and, on the Management Replacement Date,
except as otherwise set forth on Exhibit B
attached hereto and incorporated herein by reference for all purposes, the
provisions of the Management Agreement are incorporated herein by reference and
shall apply with the same force and effect as if such provisions were set forth
in full herein to the extent provided in this Section 2.1; provided, however, no implied covenants or
obligations shall be read into this Agreement or the Management Agreement
against the Back-up Manager and provided, further, that the parties to the Management
Agreement, and Appendix A, to the extent any terms in Appendix A are
used in the Management Agreement, shall not amend the same without the prior
written consent of the Back-up Manager. On the Management Replacement Date
except as set forth in Exhibit B
attached hereto and incorporated by reference for all purposes, the Back-up
Manager shall be obligated under the Management Agreement as if it were the Manager
thereunder. Notwithstanding anything contained in this Agreement or the
Management Agreement to the contrary, including without limitation,
Sections 5.2, 5.5 or 5.6 of the Management  2


Agreement, the Back-up Manager shall only be required to perform its
obligations under the Management Agreement in accordance with the Services
Standard and Applicable Law. Notwithstanding anything contained in this
Agreement, the Management Agreement or any Related Document to the contrary,
the Back-up Managers duties and obligations as Manager shall not arise until
and unless the Back-up Manager has received the Manager Termination Notice
pursuant to Section 405(a) of the Indenture.  SECTION 2.2The
parties agree as follows:  (a)The Back-up Manager has
delivered its transition plan (the Transition Plan) to the Issuer, the
Deal Agent, each Series Enhancer, and the Rating Agencies, which
Transition Plan describes, in summary detail, the steps which must be taken to
transfer the management of the Owner Compressors from the Manager to the
Back-up Manager. A copy of the Transition Plan is attached as Exhibit C hereto and
incorporated herein by reference for all purposes; and  (b)The Back-up Manager and the Manager have agreed
upon the form and substance of the systems data (including, without
limitation, the maintenance schedule, the overhaul schedule, equipment
location, billing, cash application, tax, UCC, and insurance information) and
other information that the Back-up Manager will require in order to effectively
execute the Transition Plan, including without limitation, any information
regarding Users in respect of Owner Compressors needed to effectuate any remedy
under Section 12.2 of the Management Agreement, and assume and perform the
duties of the Manager under the Management Agreement (the Systems Data).  SECTION 2.3As
compensation for the Back-up Managers performance hereunder, the Manager will
pay to the Back-up Manager on each Payment Date the Back-up Manager Fee. If UCI
shall fail to pay such Back-up Manager Fee, the Back-up Manager shall be
entitled to receive such fees from distributions from the Trust Account at the
times, in the amounts and subject to the priorities of distribution set forth
in the Indenture. Effective on the Management Replacement Date, the Back-up
Manager shall be entitled to receive the Management Fee and Incentive
Management Fee as compensation for its services hereunder and thereunder (and
its entitlement to receive the Back-up Manager Fee shall cease at such time) at
the times and in the amounts provided in the Management Agreement.  SECTION 2.4The
Manager and the Back-up Manager hereby each agree to cooperate with each other
and each Series Enhancer in effecting (a) the termination of the
responsibilities and rights of the Manager under the Management Agreement and (b) the
transfer of the responsibilities and rights from the Manager to the Back-up
Manager (or another Replacement Manager) under the Management Agreement,
including, without limitation, the preparation, execution, and delivery of any
and all documents and other instruments, the execution and delivery of
assignments of financing statements, and the transfer to the Back-up Manager
(or another Replacement Manager) for administration by it of all cash amounts
which shall at the time be held by the Manager or thereafter received by the
Manager with respect to the User Contracts and the Owner Compressors. Effective
upon the delivery of a Manager Termination Notice, the Manager hereby agrees to
transfer all Systems Data to the Indenture Trustee. Upon the Indenture Trustees
receipt of direction from the Requisite Global Majority, the Indenture Trustee
will deliver the Systems Data to the Back-up Manager and, if so directed, to
each Series Enhancer. After the delivery of the Manager Termination Notice
and on or prior to the Management Replacement Date, the Back-up Manager agrees
to set up the ABS Lockbox Account. The Back-up Manager agrees to enter into any
lockbox agreement and control agreement in connection with such ABS Lockbox
Account as may be required by the Requisite Global Majority in its sole
but reasonable discretion. Once the ABS Lockbox Account is established, the
Manager and the Back-up Manager will cooperate with each other to contact all
Users of the Owner Compressors and notify them of the change in  3


payment address from the Lockbox Account to the ABS Lockbox Account. Effective
on the Management Replacement Date, UCI hereby agrees to transfer to Back-up
Manager (or another Replacement Manager) copies of all original master contract
compression services agreements, originals (if available) of the Schedule As
thereto or any other functional equivalent, and Contract Files and all Systems
Data and copies of its electronic records and all other records, correspondence
and documents relating to the User Contracts and the Owner Compressors in the
manner and at such times as the Back-up Manager (or another Replacement
Manager) shall reasonably request and do any and all other acts or things
necessary or appropriate to effect the purposes of the termination of UCI as
Manager and the assumption of the duties of the Manager by Caterpillar. The
Manager hereby designates the Back-up Manager (or any other Replacement
Manager) as its agent and attorney-in-fact, on and after the Management
Replacement Date, to execute transfers of any agreements, documents or
instruments which may be necessary or advisable to effect such transfer of
the Managers responsibilities and rights hereunder;provided, that all reasonable expenses relating to such
actions shall be paid by the Manager.  SECTION 2.5[Intentionally
Omitted].  SECTION 2.6Nothing
in the preceding provisions of this Agreement shall be interpreted as limiting
or restricting any rights or remedies which the Issuer, the Indenture Trustee,
the Deal Agent, any Series Enhancer, the Noteholders or any other Person
would otherwise have at law or in equity on account of the breach or violation
of any provision of this Agreement, or the Management Agreement, by the Manager
or the Back-up Manager, including, without limitation, the right, subject to Sections 9.17 and 9.18 of this Agreement, to recover
full and complete damages on account thereof and, to the extent not inconsistent
with Section 12 of the Management
Agreement, injunctive relief and specific performance.  SECTION 2.7Upon
termination of its obligations as Manager under the Management Agreement, the
Manager agrees to cooperate with the Back-up Manager in those regions where the
Back-up Manager does not maintain sufficient operations to service the Owner
Compressors and, to the extent reasonably necessary in order to service and
maintain the Owner Compressors as required under the Management Agreement, (a) make
its facilities, equipment and vehicles in those regions available on an as
needed, where needed basis, (b) with the consent of the employees, provide
the Back-up Manager with an employee list which will contain job titles and
contact information and to make such employees available for interviews with
the Back-up Manager, and (c) provide for a right of first refusal to
purchase the items set forth in clause (a) of this Section 2.7
at their appraised values but only to the extent such right of first refusal is
permitted by all material agreements in effect as of the date of this Agreement
to which UCI is a party.  ARTICLE III  GENERAL PROVISIONS  SECTION 3.1Subject
to the provisions of Section 2.1,
the Back-up Manager shall fully assume, from and after the Management
Replacement Date, all of the rights (including, without limitation, rights to
any S&A Fee, Operations Fee, Overhaul Fee, and a charge for Reimbursable
Services under the Management Agreement), responsibilities, duties, and
liabilities relating thereto placed on the Manager by the terms and provisions
of the Management Agreement as though it were a party thereto as the Manager, provided,  however,
in no event shall the Back-up Manager be responsible or liable for any Claims
arising out of or in connection with actions taken or not taken by the outgoing
Manager, whether such actions were so taken or not taken prior to or following
the Management Replacement Date.  4


SECTION 3.2Following
the occurrence of a Trigger Event, the Back-up Manager agrees to perform such
additional diligence and verification duties as any Series Enhancer shall
reasonably request that are designed to facilitate the goals of the Transition
Plan. The costs and expenses of such diligence and verification shall be paid
by the Manager following the Back-up Managers presentation of an invoice
therefor.  SECTION 3.3Within
ninety (90) days after the end of each calendar year, prior to delivery of a
Manager Termination Notice, the Back-up Manager and the Manager shall perform the
duties and take the actions set forth below:  (a)The Back-up Manager
shall review the Transition Plan and, to the extent there are any material
amendments or modifications necessary, it shall deliver an updated Transition
Plan to the Issuer, the Deal Agent, any Series Enhancer, and the Rating
Agencies;  (b)The Back-up Manager and
the Manager shall agree upon material amendments or modifications, if any, to
the Systems Data;  (c)The Back-up Manager
shall review the maintenance schedule and the overhaul schedule of a
random sample of twenty-five (25) Owner Compressors to ensure compliance with
the Services Standard. The Back-up Manager shall provide a written report to
the Deal Agent, the Issuer, the Indenture Trustee, each Series Enhancer,
any Interest Rate Hedge Provider and the Manager setting forth any material
discrepancies between the scheduled maintenance and scheduled overhauls and the
actual maintenance and actual overhauls of the Owner Compressors (Status
Report);  (d)If the Manager
disagrees with the Back-up Managers assessments provided in the Status Report
or if the Manager has not resolved any material discrepancies between the
scheduled maintenance and overhauls and the actual maintenance and overhauls of
the Owner Compressors, the Back-up Manager agrees to (i) confer with the
Manager to resolve such disagreements and/or discrepancies on or prior to the
next succeeding Determination Date, and (ii) notify in writing the Deal
Agent, the Indenture Trustee, and each Series Enhancer of the resolution
or non-resolution thereof. The Manager hereby agrees to cooperate, at its own
expense, with the Back-up Manager in reconciling any material discrepancies
identified by the Back-up Manager in the Status Report. If such material
discrepancy is not resolved, the Back-up Manager shall promptly notify the
Indenture Trustee and each Series Enhancer of such non-resolution. Following
such non-resolution, the Manager shall deliver to the Deal Agent, the Rating
Agencies, each Series Enhancer, the Back-up Manager, any Interest Rate
Hedge Provider and the Indenture Trustee no later than the next succeeding
Payment Date a certificate describing the nature and cause of such material
discrepancies; and  (e)The Back-up Manager
will make a site visit to the offices of the Manager for the purpose of
reviewing the operations of the Manager. Such inspections shall be made upon
the giving of reasonable advance notice and will be conducted during normal
business hours and the reasonable out-of-pocket expenses of the Back-up Manager
incurred in connection with such visit shall be paid by the Manager.  5


ARTICLE IV  TERM  SECTION 4.1This
Agreement shall continue in force with respect to all Owner Compressors until
the earliest to occur of (a) the destruction, loss, sale, or other
disposition of all Owner Compressors in accordance with the terms of the
Related Documents, (b) the date on which the Indenture is discharged in
accordance with its terms, or (c) the date on which the Indenture Trustee
(acting at the written direction of the Requisite Global Majority), a Series Enhancer
or the Manager (acting at the written direction of the Requisite Global
Majority), terminates all rights and obligations of the Back-up Manager
hereunder by delivery to the Back-up Manager of a notice of termination (the Back-up Manager Termination Notice)
executed by the Indenture Trustee (at the written direction of the Requisite
Global Majority).  SECTION 4.2If
a Back-up Manager Termination Notice is received by the Back-up Manager while
it is performing its duties hereunder, the Back-up Manager agrees to cooperate
with the Issuer, the Indenture Trustee, each Series Enhancer, and any
Interest Rate Hedge Provider, the Replacement Manager or the successor Back-up
Manager in effecting the termination of the Back-up Managers responsibilities
and rights hereunder, including, without limitation, the transfer to the
Replacement Manager or the successor Back-up Manager of all data then in the
possession of the Back-up Manager.  SECTION 4.3The
Back-up Manager shall not resign from the obligations and duties hereby imposed
on it as Back-up Manager except (a) with the prior written consent of the Requisite
Global Majority, or (b) upon determination that the performance of its
duties hereunder is no longer permissible under Applicable Law. Any such
determination permitting the resignation of the Back-up Manager shall be
evidenced by an opinion of counsel to the Back-up Manager to such effect
delivered to each Series Enhancer and to the Rating Agencies. Upon the
Back-up Managers resignation or termination pursuant to Sections 4.1
or 4.3 hereof, the Back-up Manager shall comply with the
provisions of this Agreement until the acceptance of appointment and
commencement of the Back-up Managers duties by a successor Back-up Manager. Any
such successor Back-up Manager shall be appointed by the Requisite Global
Majority.  ARTICLE V  NO FORCE MAJEURE  The obligations of each of the Issuer,
Manager, and Back-up Manager under this Agreement are unconditional and shall
not be subject to suspension, delay or interruption on account of the
occurrence of any event, whether or not such event is beyond its control.  ARTICLE VI  INDEMNIFICATION  SECTION 6.1The
Issuer and the Manager each agree to, and hereby do, severally (as to Claims
arising as a result of such Persons action, inaction or breach) defend,
indemnify, and hold harmless the Back-up Manager, its successors and assigns,
and its and their respective officers, directors, employees, and agents (each
of the foregoing, a Back-up Manager
Indemnified Party) from and against any and all claims,
actions, damages, losses, liabilities, costs and expenses (including reasonable
legal fees) (each a Claim)
incurred by or asserted against such Back-up Manager Indemnified Party to  6


the extent resulting, arising from or related to this Agreement, the
Management Agreement, any Related Document or the transactions contemplated
thereby, including but not limited to those resulting or arising from (a) an
action or inaction by such Issuer or Manager, as the case may be, that is
contrary to the terms of any Related Document, (b) a breach by the Issuer
or Manager, as the case may be, of its representations and covenants set
forth in any Related Document which results in a Material Adverse Change, or (c) any
information certified in any schedule or report delivered by the Issuer or
Manager, as the case may be, being untrue in any material respect as of
the date of such certification, except for Claims which arise out of a Back-up
Manager Indemnified Partys willful misconduct, gross negligence, or failure to
comply with or perform its obligations under this Agreement or the
Management Agreement,provided, that
the foregoing indemnity shall in no way be deemed to impose on the Issuer or
the Manager any obligation to reimburse a Back-up Manager Indemnified Party for
losses to the extent arising from the failure of the related obligor on a User
Contract to make contract payments and other service-related payments. The
Back-up Manager subordinates its Claims against the Issuer under this Section 6.1 to all Claims
which have priority in payment under the provisions of the Indenture, and
further agrees that any such Claims shall (a) be nonrecourse to the Issuer,
(b) only be payable at the times and in the amounts for which funds are
available for such purpose pursuant to the provisions of the Indenture, and (c) not
constitute a claim (as defined in Section 101(5)of
the Bankruptcy Code) against the Issuer.  SECTION 6.2The
Back-up Manager agrees to, and hereby does, defend, indemnify, and hold
harmless the Issuer, the initial Manager, each Entitled Party, and its and
their respective officers, directors, employees and agents (each of the
foregoing, an Indemnified Party)
from and against any and all Claims incurred by or asserted against such
Indemnified Party to the extent resulting or arising from (a) an action or
inaction by the Back-up Manager that is contrary to the terms of this Agreement
or the Management Agreement, (b) a breach by the Back-up Manager of its
representations and covenants set forth in this Agreement which results in a Material
Adverse Change, or (c) any information certified in any schedule or
report delivered by the Back-up Manager being untrue in any material respect as
of the date of such certification, except for Claims which arise as a result of
an Indemnified Partys willful misconduct, gross negligence, or failure to
comply with or perform its obligations under any Related Document, providedthat the foregoing indemnity shall in no way be
deemed to impose on the Back-up Manager any obligation to reimburse an
Indemnified Party for losses arising solely from the financial inability of the
related User on a User Contract to make contract payments and other
service-related payments.  SECTION 6.3The
rights and obligations of the Back-up Manager Indemnified Parties and the
Indemnified Parties under this Section 6
shall survive the resignation or removal of the Back-up Manager and the
termination of this Agreement.  ARTICLE VII  NO BANKRUPTCY PETITION AGAINST ISSUER  The Back-up Manager will not, prior to the
date that is one (1) year and one (1) day after the payment in full
of all Outstanding Obligations under the Indenture and all Supplements,
institute against the Issuer, or join any other Person in instituting against
the Issuer, an Insolvency Proceeding. This Section 7
shall survive the resignation of the Back-up Manager and the termination of
this Agreement.  7


ARTICLE VIII  REPRESENTATIONS AND WARRANTIES  SECTION 8.1The
Back-up Manager represents and warrants to the Manager, each Entitled Party and
the Issuer that:  (a)The Back-up Manager is
a corporation duly organized, validly existing and in good standing under the
laws of Delaware;  (b)The Back-up Manager has
the requisite power and authority to enter into and perform its obligations
under this Agreement, and all requisite corporate authorizations have been
given for it to enter into this Agreement and to perform all the matters contemplated
hereby. This Agreement has been duly executed and delivered by the Back-up
Manager. Upon due execution and delivery hereof by the other parties hereto
this Agreement will constitute the valid, legally binding, and enforceable
obligation of the Back-up Manager, subject to bankruptcy, insolvency,
moratorium, reorganization, and other laws of general applicability relating to
or affecting creditors rights and to general equity principles; and  (c)The Back-up Manager has
not breached its certificate of incorporation or by-laws or any other agreement
to which it is a party or by which it is bound in the course of conduct of its
business and corporate affairs or any Applicable Laws in such manner as would
in any such case have a materially adverse effect on its ability to perform its
obligations under this Agreement.  SECTION 8.2The
Issuer represents and warrants to the Manager, the Indenture Trustee, the Deal
Agent, each Series Enhancer, each Interest Rate Hedge Provider and the
Back-up Manager that:  (a)It is a limited
liability company duly formed, validly existing and in good standing under the
laws of the State of Delaware;  (b)It has the requisite
power and authority to enter into and perform its obligations under this
Agreement, and all requisite authorizations have been given for it to enter
into this Agreement and to perform all the matters contemplated hereby. Upon
due execution and delivery hereof, this Agreement will constitute the valid,
legally binding and enforceable obligation of the Issuer, subject to
bankruptcy, insolvency, moratorium, reorganization and other laws of general applicability
relating to or affecting creditors rights and to general equity principles;
and  (c)It has not breached its
organizational documents or any other agreement to which it is a party or by
which it is bound in the course of conduct of its business and affairs or any
Applicable Laws in such a manner as would in any such case result in a Material
Adverse Change.  SECTION 8.3The
Manager represents and warrants to the Indenture Trustee, the Deal Agent, each Series Enhancer,
the Back-up Manager, each Interest Rate Hedge Provider and the Issuer that:  (a)The Manager is a
corporation duly organized, validly existing and in good standing under the
laws of Texas;  8


(b)The Manager has the
requisite power and authority to enter into and perform its obligations
under this Agreement, and all requisite corporate authorizations have been
given for it to enter into this Agreement and to perform all the matters contemplated
hereby. Upon due execution and delivery hereof this Agreement will constitute
the valid, legally binding and enforceable obligation of the Manager, subject
to bankruptcy, insolvency, moratorium, reorganization and other laws of general
applicability relating to or affecting creditors rights and to general equity
principles; and  (c)The Manager has not
breached its certificate of incorporation or by-laws or any other agreement to
which it is a party or by which it or its property is bound in the course of
conduct of its business and corporate affairs or any Applicable Laws in such
manner as would in any such case (x) result in a Material Adverse Change
or (y) have a material adverse effect on the rights and remedies of the Issuer
hereunder.  ARTICLE IX  GENERAL  SECTION 9.1All
demands, notices and communications hereunder shall be in writing and
personally delivered or sent by facsimile (with subsequent telephone
confirmation of receipt thereof) or sent by internationally recognized
overnight courier service, to the following addresses:  To Manager:
  
  Universal Compression, Inc4444 Brittmoore RoadHouston, Texas 77041Telephone: (713) 335-7295Facsimile:  (713) 446-6720Attention:  J. Michael AndersonTo Issuer:
  
  UCO Compression 2005 LLC4444 Brittmoore RoadHouston, Texas 77041Telephone: (713) 335-7295Facsimile:  (713) 446-6720Attention:  J. Michael AndersonTo Back-up Manager:
  
  Caterpillar Inc.100 NE Adams StreetPeoria, Illinois 61629Telephone: (309) 675-1000Facsimile:  (309) 675-6620Attention:  General CounselTo the Indenture Trustee:
  
  Wells Fargo Bank, National AssociationMAC N9311-161Sixth Street and Marquette AvenueMinneapolis, MN 55479Telephone: (612) 667-7181Facsimile: (612) 667-3464Attention: Corporate Trust Services
  -Asset-Backed
  Administration  9


To the Deal Agent:
  
  Wachovia Capital Markets LLCStructured Asset Finance301 S. College St., Mailcode:  NCO610Charlotte, North Carolina 28288-0610Telephone: (704) 383-8608Facsimile:  (704) 374-3254Attention:  Manoj KumarTo any Series Enhancer:
  
  At the address as set forth in
  the related Enhancement AgreementTo the Rating Agencies:
  
  Standard & Poor Ratings Group55 Water Street, 40th FloorNew York, New York 10041-0003Telephone: (212) 425-7025Facsimile:  (212) 208-1393Moodys Investors Services99 Church Street, 4th FloorNew York, New York 10007Telephone: (212) 553-0300Facsimile:  (212) 553-0574Attention:  Asset Backed Monitoring
  GroupTo any Interest Rate HedgeProvider:
  
  At the address as set forth in
  related Interest Rate SwapAgreement  Notice shall be effective and deemed received (a) two (2) days
after being delivered to the courier service, if sent by courier, (b) upon
receipt of confirmation of transmission, if sent by telecopy or email, or (c) when
delivered, if delivered by hand or certified first class mail, return
receipt requested. Each party delivering a notice hereunder shall deliver a
copy of such notice to the Deal Agent at the address set forth above.  SECTION 9.2If
any proceeding is brought for enforcement of this Agreement or because of an
alleged dispute, breach, or default in connection with any provision of this
Agreement, the prevailing party shall be entitled to recover, in addition to
other relief to which it may be entitled, reasonable attorney fees and
other reasonable costs incurred in connection therewith.  SECTION 9.3The
Back-up Manager, the Issuer, and the Manager shall each perform such
further acts and execute such further documents as may be necessary to
implement the intent of, and consummate the transactions contemplated by, this
Agreement.  SECTION 9.4If
any term or provision of this Agreement or the performance thereof shall to any
extent be or become invalid or unenforceable, such invalidity or
unenforceability shall not affect or render invalid or unenforceable any other
provision of this Agreement and this Agreement shall continue to be valid and
enforceable to the fullest extent permitted by law.  10


SECTION 9.5  (a)This Agreement shall be binding upon and
inure to the benefit of, and be enforceable by, the Issuer, the Manager, and
the Back-up Manager, and their respective successors in interest and permitted
assigns; provided, however, that:  (i) this
Agreement and the rights and duties of the Back-up Manager hereunder may not
be assigned by the Back-up Manager to any other Person, other than to an
Affiliate of the Back-up Manager, without the prior written consent of the Issuer
and the Indenture Trustee (at the written direction of the Requisite Global
Majority), and (ii) the Issuer may charge, assign, pledge, or
hypothecate their rights (but not their obligations) under this Agreement as
provided herein. The Back-up Manager hereby acknowledges that the Issuer will
assign all of its right, title, and interest under this Agreement to the
Indenture Trustee, each Series Enhancer and the beneficiaries under the
Indenture will each be a beneficiary of such assignment. The Back-up Manager
hereby consents to such assignment. The Back-up Manager shall give the Rating
Agencies prior written notice of any assignment of the Back-up Managers rights
or obligations hereunder effected pursuant to this Section 9.5.  (b)Any Person (i) into
which the Back-up Manager may be merged or consolidated, (ii) which may result
from any merger or consolidation to which the Back-up Manager shall be a party,
or (iii) which may succeed to the properties and assets of the
Back-up Manager substantially as a whole, which Person in any of the foregoing
cases executes an agreement of assumption to perform every obligation of
the Back-up Manager hereunder, shall be the successor to the Back-up Manager
under this Agreement without further act on the part of any of the parties
to this Agreement. In the event that the resulting entity is not acceptable to
any Series Enhancer in its sole discretion, the Back-up Manager, upon
written request of any Series Enhancer, shall resign from its obligations
and duties under this Agreement. Such resignation shall not become effective
until a successor Back-up Manager, appointed by the Requisite Global Majority,
has accepted such appointment.  (c)Notwithstanding any
provision of this Section 9, the Back-up Manager may subcontract
its duties under this Agreement or the Management Agreement to any qualified
and recognized industry participant to perform the duties of the Back-up
Manager or the Replacement Manager, with the prior written consent of each Series Enhancer;
provided that the Back-up Manager
shall remain responsible notwithstanding such subcontractor. On the Effective
Date, the Back-up Manager shall engage Compressor Systems, Inc. as a
subcontractor, which such subcontractor is acceptable to the Series Enhancers.  SECTION 9.6Waiver
of any term or condition of this Agreement (including any extension of time
required for performance) shall be effective only if in writing and shall not
be construed as a waiver of any subsequent breach or waiver of the same term or
condition or a waiver of any other term or condition of this Agreement. No
delay on the part of any party in exercising any right, power, or
privilege hereunder shall operate as a waiver hereof.  SECTION 9.7The
headings contained in this Agreement are for reference purposes only and shall
not affect in any way the meaning or interpretation of this Agreement.  SECTION 9.8This
Agreement and the appendices attached hereto represent the entire agreement
between the parties with respect to the subject matter hereof and may not
be amended or modified except by an instrument in writing signed by the parties
hereto and approved by the Requisite Global Majority. The Back-up Manager shall
send prior notice of any amendment or modification to the Rating Agencies.  11


SECTION 9.9If
Caterpillar or any successor Back-up Manager becomes the Replacement Manager, a
new Back-up Manager shall be appointed by the Series Enhancers, at their
option, and approved by the Replacement Manager.  SECTION 9.10This
Agreement may be signed in counterparts each of which shall constitute an
original instrument, but all of which together shall constitute but one and the
same instrument.  SECTION 9.11Any
signature required with respect to this Agreement may be provided via
facsimile; provided that the originals of such
signatures are supplied by each party to the other party promptly thereafter.  SECTION 9.12THIS
AGREEMENT SHALL BE CONSTRUED BY AND INTERPRETED IN ACCORDANCE WITH THE LAWS OF
THE STATE OF NEW YORK INCLUDING SECTIONS 5-1401 AND 5-1402 OF THE GENERAL
OBLIGATIONS LAWS BUT OTHERWISE WITHOUT GIVING EFFECT TO THE PRINCIPLES OF
CONFLICTS OF LAW THAT WOULD RESULT IN APPLICATION OF LAWS OTHER THAN NEW YORK,
AND THE RIGHTS, OBLIGATIONS AND REMEDIES OF THE PARTIES HERETO SHALL BE
DETERMINED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.  SECTION 9.13ANY
LEGAL SUIT, ACTION OR PROCEEDING AGAINST THE BACK-UP MANAGER, THE MANAGER OR
THE ISSUER ARISING OUT OF OR RELATING TO THIS AGREEMENT, OR ANY TRANSACTION
CONTEMPLATED HEREBY, MAY BE INSTITUTED IN ANY FEDERAL OR STATE COURT IN
NEW YORK COUNTY, STATE OF NEW YORK AND THE MANAGER, THE BACK-UP MANAGER, AND
THE ISSUER EACH HEREBY WAIVE ANY OBJECTION WHICH IT MAY NOW OR HEREAFTER
HAVE TO THE LAYING OF VENUE OF ANY SUCH SUIT, ACTION OR PROCEEDING, AND, SOLELY
FOR THE PURPOSES OF ENFORCING THIS AGREEMENT, EACH OF THE PARTIES HERETO EACH
HEREBY IRREVOCABLY SUBMITS TO THE JURISDICTION OF ANY SUCH COURT IN ANY SUCH
SUIT, ACTION OR PROCEEDING EACH OF THE PARTIES HEREBY IRREVOCABLY APPOINTS AND
DESIGNATES CT CORPORATION SYSTEM HAVING AN ADDRESS AT 111 EIGHTH AVENUE, NEW
YORK, NEW YORK 10011, ITS TRUE AND LAWFUL ATTORNEY-IN-FACT AND DULY AUTHORIZED
AGENT FOR THE LIMITED PURPOSE OF ACCEPTING SERVICE OF LEGAL PROCESS AND EACH OF
THE PARTIES HERETO EACH AGREE THAT SERVICE OF PROCESS UPON SUCH PARTY SHALL
CONSTITUTE PERSONAL SERVICE OF SUCH PROCESS ON SUCH PERSON. EACH OF THE PARTIES
HERETO SHALL EACH MAINTAIN THE DESIGNATION AND APPOINTMENT OF SUCH AUTHORIZED
AGENT UNTIL ALL AMOUNTS PAYABLE UNDER THIS AGREEMENT AND THE INDENTURE SHALL
HAVE BEEN PAID IN FULL. IF SUCH AGENT SHALL CEASE TO SO ACT, EACH OF THE PARTIES
HERETO SHALL IMMEDIATELY DESIGNATE AND APPOINT ANOTHER AGENT SATISFACTORY TO
THE INDENTURE TRUSTEE AND SERIES ENHANCERS AND SHALL PROMPTLY DELIVER TO
THE INDENTURE TRUSTEE EVIDENCE IN WRITING OF SUCH OTHER AGENTS ACCEPTANCE OF
SUCH APPOINTMENT.  SECTION 9.14EACH OF
THE PARTIES HERETO HEREBY IRREVOCABLY WAIVES, AS AGAINST THE OTHER PARTIES
HERETO, ANY RIGHTS IT MAY HAVE TO A JURY TRIAL IN RESPECT OF ANY CIVIL
ACTION OR PROCEEDING (WHETHER ARISING IN CONTRACT OR TORT OR OTHERWISE),
INCLUDING ANY COUNTERCLAIM, ARISING UNDER OR RELATING TO THIS AGREEMENT OR ANY
OTHER OPERATIVE DOCUMENT, INCLUDING IN RESPECT OF THE NEGOTIATION,
ADMINISTRATION OR ENFORCEMENT HEREOF OR THEREOF.  12


SECTION 9.15To the
extent that any party hereto or any of its property is or becomes entitled at
any time to any immunity on the grounds of sovereignty or otherwise from any
legal actions, suits or proceedings, from set-off or counterclaim, from the
jurisdiction or judgment of any competent court, from service of process, from
execution of a judgment, from attachment prior to judgment, from attachment in
aid of execution, or from execution prior to judgment, or other legal process
in any jurisdiction, such party, for itself and its successors and assigns and
its property, does hereby irrevocably and unconditionally waive, and agrees not
to plead or claim, any such immunity with respect to its obligations,
liabilities, or any other matter under or arising out of or in connection with
this Agreement, the other Related Documents or the subject matter hereof or
thereof, subject, in each case, to the provisions of the Related Documents and
mandatory requirements of applicable law.  SECTION 9.16The
parties hereto (A) acknowledge that the matters contemplated by this
Agreement are part of a financing transaction and (B) hereby agree
that (i) specification and payment of Dollars is of the essence, (ii) Dollars
shall be the currency of account in the case of all obligations under the Related
Documents unless otherwise expressly provided herein or therein, (iii) the
payment obligations of the parties under the Related Documents shall not be
discharged by an amount paid in a currency or in a place other than that
specified with respect to such obligations, whether pursuant to a judgment or
otherwise, except to the extent actually received by the Person entitled
thereto and converted into Dollars by such Person (it being understood and
agreed that, if any transaction party shall so receive an amount in a currency
other than Dollars, it shall (A) if it is not the Person entitled to
receive payment, promptly return the same (in the currency in which received)
to the Person from whom it was received or (B) if it is the Person
entitled to receive payment, either, in its sole discretion, (x) promptly
return the same (in the currency in which received) to the Person from whom it
was received or (y) subject to reasonable commercial practices, promptly
cause the conversion of the same into Dollars), (iv) to the extent that
the amount so paid on prompt conversion to Dollars under normal commercial
practices does not yield the requisite amount of Dollars, the obligee of such
payment shall have a separate cause of action against the party obligated to
make the relevant payment for the additional amount necessary to yield the
amount due and owing under the Related Documents, (v) if, for the purpose
of obtaining a judgment in any court with respect to any obligation under any
of the Related Documents, it shall be necessary to convert to any other
currency any amount in Dollars due thereunder and a change shall occur between
the rate of exchange applied in making such conversion and the rate of exchange
prevailing on the date of payment of such judgment, the obligor in respect of
such obligation will pay such additional amounts (if any) as may be
necessary to insure that the amount paid on the date of payment is the amount
in such other currency which, when converted into Dollars and transferred to
New York City, New York, in accordance with normal banking procedures, will
result in realization of the amount then due in Dollars and (vi) any
amount due under this paragraph shall be due as a separate debt and shall not
be affected by or merged into any judgment being obtained for any other sum due
under or in respect of any Related Document. In no event, however, shall the
respective judgment debtor be required to pay a larger amount in such other
currency, at the rate of exchange in effect on the date of payment than the
amount of Dollars stated to be due under the respective Related Document, so
that in any event the obligations of the respective judgment debtor under the
Related Document will be effectively maintained as Dollar obligations.  SECTION 9.17The
Back-up Manager and Manager hereby irrevocably and unconditionally waive all
right of set-off that they may have under contract (including this
Agreement), Applicable Law, or otherwise with respect to any funds or monies of
the Issuer, at any time held by or in the possession of the Back-up Manager.  SECTION 9.18THE
BACK-UP MANAGER SHALL NOT UNDER ANY CIRCUMSTANCES BE LIABLE TO THE ISSUER, THE
MANAGER, AND/OR TO ANY OTHER PARTY CLAIMING RIGHTS UNDER THIS AGREEMENT AND/OR
THE MANAGEMENT  13


AGREEMENT FOR INCIDENTAL, INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES,
OR FOR LOST PROFITS, SAVINGS OR REVENUES OF ANY KIND, WHETHER OR NOT THE
BACK-UP MANAGER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.  SECTION 9.19Each of
the Indenture Trustee, the Deal Agent, and each Series Enhancer shall be
third party beneficiaries of this Agreement and shall be entitled to enforce
the rights and obligations of the Manager and the Back-up Manager hereunder as
though it were a party thereto. Each party hereto agrees that, if the Indenture
Trustee shall fail to act hereunder as directed by the Requisite Global
Majority at any time at which it is so required hereby or by any Related
Document, then the Requisite Global Majority shall be entitled to directly
enforce the provisions of this Agreement or take any such action directly in
its own capacity or on behalf of the Indenture Trustee in accordance with the
terms of this Agreement and, in the event any party receives instructions from
both the Indenture Trustee and the Requisite Global Majority, such party may act
on and rely upon the instructions from the Requisite Global Majority.  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK -SIGNATURE PAGE FOLLOWS]  14


IN WITNESS WHEREOF,the
parties hereto have executed this Agreement as of the day and year first above
written.   UNIVERSAL COMPRESSION, INC.By:
  /s/ J. Michael AndersonJ. Michael Anderson, Senior Vice President andChief Financial OfficerUCO COMPRESSION 2005, LLCBy:
  /s/ J. Michael AndersonJ. Michael Anderson, Senior Vice President andChief Financial OfficerCATERPILLAR INC.By:
  /s/ James J. ParkerName:
  James J. ParkerTitle:
  Vice President


EXHIBITB  Exceptions and/or Modifications to
Provisions of the Management Agreement to be effective on the Management
Replacement Date:  1.Except as set forth
in this Exhibit B or where
references are to Universal, UCI or Universal as Manager or similar
language which is intended to only apply to UCI or its Affiliates, all
references in the Management Agreement to Manager shall refer to Caterpillar
(or any appointed subcontractor), and such terms shall be amended mutatis mutandis.  2.All obligations of  UCI, as the initial Manager,
to pay expenses of the Issuer and each Entitled Party during a Trigger Event
shall remain the obligation of UCI.  3.Section 9.10 shall be amended to require the Issuer to
bear all expenses associated with any Appraisals.  4.The following sections will be deleted in
their entirety:  Sections 5.2(b),
5.7(d), 5.13,
5.14,  9.1(g), 9.1(m),  9.1(n),  9.1(o),
and 9.11.  5.Section 4.2
will be amended to only require the Manager to pay and discharge Lien Claims
that result from claims of Persons against the Manager resulting from an act or
omission by the Manager or the Managers willful misconduct, negligence or
failure to perform its duties or obligations under the Management Agreement in
accordance therewith.  6.Section 5.7
will be amended to require the Manager to cause to be obtained at the expense
of the Issuer, the insurance required in Sections 5.7(a)
through 5.7(c).  7.Section 5.8
will be amended to only require indemnification from the Manager of the
obligations required therein to the extent the resulting Taxes and Impositions
were caused by the gross negligence or willful misconduct of the  Manager. 
In addition, the following two (2) sentences shall be inserted between
the second (2nd) and third (3rd) sentences of Section
5.8:  The Manager
will calculate the amount of Impositions due that are not Excluded Payments and
submit such calculations to the Issuer and the Indenture Trustee, to be
included as part of the Operations Fee. 
Following the delivery of such calculations and the payment of such
amounts to the Manager pursuant to either a distribution under Section 302(c)
at the Managers request or on the next Payment Date pursuant to Section 302(d)
or 302(e) of the Indenture, as applicable, the Manager will promptly pay all
such amounts to the appropriate Governmental Authority.  8.Sections 5.11, 9.2 and 19.8 will be amended to reflect Caterpillars offices in lieu of
UCIs address.  9.Section 7.1(a) is deleted in its entirety and the following
is inserted in substitution thereof:  (a)After
the delivery of the Manager Termination Notice and on or prior to the
Management Replacement Date, the Manager agrees to set up and maintain the ABS
Lockbox Account.  The Manager agrees to
enter into any lockbox agreement and control agreement in connection with such
ABS Lockbox Account as may be required by the Requisite Global Majority in its
sole but reasonable discretion.  Once the
ABS Lockbox Account is established, UCI and the Manager agree to cooperate to
contact all Users of the Owner Compressors and notify them of the change in
payment address from the Lockbox Account to the ABS Lockbox Account.  The Manager  1


agrees to
promptly return to UCI all receipts, receivables, proceeds and other
collections it may receive which is not related to Securitization
Collateral.  UCI agrees to promptly
deposit to the ABS Lockbox Account all receipts, receivables, proceeds and
other collections it may receive which is Securitization Collateral.  10.          Section 7.3 is deleted in its
entirety and the following is inserted in substitution thereof:  The Manager
shall be entitled to request withdrawals (and the Indenture Trustee upon
written notice from the Manager shall make such withdrawals) of the Operations
Fee, S&A Fee and Overhaul Fee from the Collection Account in accordance
with Section 302 of the Indenture.  11.          Section 9.1(a)
will bedeemed satisfied
by Caterpillar if Caterpillar shall have timely made the information
required by Section 9.1(a) available on EDGAR and/or on its home page on the
worldwide web (at the date of this Agreement located at http://www.cat.com);
provided, however, that if any Series Enhancer or Indenture Trustee is
unable to access EDGAR or Caterpillars home page on the worldwide web or is
unable to access such information from such sources, Caterpillar agrees to
provide such Series Enhancer or Indenture Trustee, as the case may be, with
paper copies of the information required to be furnished pursuant to Section
9.1(a) promptly following notice from such Series Enhancer or Indenture
Trustee, as the case may be.  Information
required to be delivered pursuant to Section 9.1(a) shall be deemed to have
been delivered on the date on which Caterpillar provides notice to the Series
Enhancers and Indenture Trustee that such information has been posted on
EDGAR or Caterpillars website or another website identified in such notice
and accessible by the Series Enhancers or Indenture Trustee without charge (and
Caterpillar hereby agrees to provide such notice).  In the event that Caterpillar is no longer
required to file quarterly or annual reports with the SEC or any successor
agency pursuant to Section 13 or 15(d) of the Exchange Act, Caterpillar agrees
to provide each Series Enhancer and Indenture Trustee with paper copies of the
information required to be furnished pursuant to Section 9.1(a) when and as if
Caterpillar was required to file such quarterly and annual reports with the SEC
or any successor agency pursuant to Section 13 or 15(d) of the Exchange Act.  12.          Section 9.1(l)
will be modified to reflect that such notice shall be required only in
connection with a Manager Default.  13.          Sections 9.3
will be modified to reflect that the inspection right described in clause (ii)
of the last sentence of such Section shall be at the expense of the Issuer.  2


EXHIBIT
C  Back-Up Manager Transition Plan   The Fleet Management process
involves three primary activities  I. Marketing
and Remarketing of Contract Compression as units become available.  II.        Maintenance,
operation and periodic overhauls of compression units  III.      Billing
and collection of Contract Compression payments in accordance with contract
terms.  I.         MARKETING       Utilization rates are relatively
consistent for both Universal and across the industry        A limited number of people are needed for
marketing duties.       Universal currently employs 35-40 sales
people for its entire domestic fleet operations. The ABS fleet represents
approximately 25% of the domestic fleet.       The marketing force required is more a
function of the customer base and its geographic dispersion rather than the
number of units.       CSI has substantial geographic and customer
overlap with Universal and would have to add a minimal number of people,
approximately (10-15), to market the ABS fleet units.       The sales staff and equipment of the
companies within the industry are well known to each other.  A number of the sales people  have worked for multiple companies within the
industry.        With a large percentage of the Securitized
Units operating under contract at any given time, any remarketing efforts
required due to a change of the Manager would be gradual and therefore minimize
the impact.       A gas producer generally incurs large
costs and production delays to swap out a compressor unit.       With a limited number of Contract
Compression providers, all operating at relatively high utilization rates, a
producer would have a high degree of difficulty finding replacement units.       Universal would be prohibited from
replacing a Securitization unit for a period of time.        The Trustee maintains current schedules of
all contracts, customer and billing information.  1


II.            MAINTENANCE        The Trustee holds the current maintenance
information        Caterpillars dealer network currently
services compressor equipment and the majority of Universals compressor
engines are manufactured by Caterpillar.        There is a high degree of similarity
between the ABS fleet units and the 425,000 horsepower owned, leased and
maintained by CSI.       CSI has over 550 employees, including
approximately 240 technicians.  2


      CSI would require approximately 300
additional technicians to service the ABS fleet, most of whom could be acquired
from Universal.    III.          BILLING
& COLLECTION        The Trustee will hold current billing and
customer information.        Substantial overlap of customers .  Collections requires minimal
resources       A majority of the large customers are
investment grade.       Billing process is automated.  3


      Ability to interrupt gas flow of producer
for non-payment leads to few collection problems.       No additional billing or collection staff
required.    4