EXHIBIT 10.29.1

                                 LOAN AGREEMENT

         THIS LOAN  AGREEMENT  (this  "Agreement"),  is made as of  September 7,
2001, by and between Probex Corp., a Delaware  corporation (the "Company"),  and
the  lenders  listed  on  Schedule  A  attached  hereto  (each a  "Lender"  and,
collectively, the "Lenders").

         WHEREAS,  the  Company  desires  to borrow  from the  Lenders,  and the
Lenders  desire  to  lend to the  Company  the  aggregate  principal  amount  of
$3,000,000,  such  indebtedness to be evidenced by promissory  notes in the form
attached  hereto as Exhibit A (as amended,  modified  and restated  from time to
time, the "Notes").

         NOW THEREFORE, for valuable consideration,  the receipt and adequacy of
which are hereby  acknowledged,  the  Lenders and the  Company  hereby  agree as
follow:

         1.  AGREEMENT  TO LEND.  Subject  to the terms and  conditions  of this
Agreement and the Loan Documents (as defined  below),  the Lenders agree to lend
to the Company  $3,000,000 in aggregate  principal amount and the Company agrees
to issue to each Lender (payable to the order of such Lender or its nominee,  if
any, set forth on Schedule A) a Note evidencing the principal  amount  specified
opposite such Lender's name in Schedule A hereto at the Closing  provided for in
Section 2. The  obligation  of each  Lender  shall be several  and not joint and
shall be limited to the principal  amount set forth  opposite such Lender's name
in Schedule A hereto and no Lender shall have any obligation or any liability to
any person for the performance or non-performance by any other Lender hereunder.

         2. CLOSING.  The closing (the "Closing")  shall occur at the offices of
Proskauer  Rose LLP, 1585  Broadway,  New York,  New York 10036,  at 10:00 a.m.,
Eastern time, on September 7, 2001 or on such other  business day  thereafter as
may be agreed upon by the Company and the Lenders (the "Closing Date").

         (a) Closing  Deliveries  of the Company.  At the  Closing,  the Company
shall  deliver to the Lenders the  following,  all of which shall be in form and
content satisfactory to the Lenders and their counsel:

               (i)  Opinion.  An opinion of  counsel of Jenkens &  Gilchrist,  a
Professional  Corporation,  counsel to the Company,  dated as of the Closing, in
the form of  Exhibit D  attached  hereto  and an opinion of counsel of Jenkens &
Gilchrist  Parker Chapin LLP,  special  counsel to the Company,  dated as of the
Closing, in the form of Exhibit E attached hereto.

               (ii)  Notes.  Each Note made  payable to the  persons  and in the
amounts set forth in Schedule A attached hereto.

               (iii) Intercreditor and Security Agreement. The Intercreditor and
Security Agreement, duly executed and delivered by the Company, in substantially
the form set forth in Exhibit B attached hereto (the "Security Agreement").

               (iv)  Registration  Rights  Agreement.  The  Registration  Rights
Agreement, duly executed and delivered by the Company, in substantially the form
set forth in Exhibit C attached hereto (the "Registration Rights Agreement", and
together  with the Security  Agreement  and the Notes,  collectively,  the "Loan
Documents").

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               (v)  Evidence  of Filing of  Financing  Statements.  Evidence  of
filing of Uniform  Commercial  Code  financing  statements  with  respect to the
collateral which is the subject of the Security Agreement.

               (vi) Payment of Special Counsel Fees. The Company shall have paid
on or before the Closing the reasonable fees,  charges and  disbursements of the
Lenders' special counsel.

         (b) Closing  Deliveries  of the Lenders.  At the  Closing,  the Lenders
shall  deliver  the  aggregate  original  principal  amount  of the Notes to the
Company in immediately available funds wired in accordance with the instructions
set forth on Schedule C.

         3. REPRESENTATIONS OF THE COMPANY.

         (a) The  representations  and  warranties  made by the  Company  in the
Security  Agreement are as fully a part of this Agreement as if set forth herein
in full.

         (b) The Company further represents and warrants to the Lenders that:

               (i)  The  Notes  are  duly  authorized  and,  when  issued,  will
constitute valid and binding obligations of the Company, enforceable against the
Company,  in  accordance  with their terms,  subject to  applicable  bankruptcy,
insolvency or similar laws  affecting  creditors'  rights  generally and general
principles of equity and except as rights to  indemnification  and  contribution
under the Notes as may be limited under applicable law;

               (ii) The  shares of the  Company's  common  stock  issuable  upon
extension  of the  maturity  date of the Notes (the  "Extension  Shares"),  when
issued, will be duly authorized,  validly issued,  fully-paid and nonassessable;
and

               (iii) The shares of the Company's common stock or preferred stock
issuable upon  conversion of the Note (the  "Conversion  Shares"),  when issued,
will be duly authorized, validly issued, fully-paid and nonassessable.

         4.  REPRESENTATIONS  OF THE lendERS.  Each Lender represents that it is
purchasing  the Notes for its own account or for one or more  separate  accounts
maintained  by it for the account of one or more  pension or trust funds and not
with a view to the distribution  thereof.  Each Lender  represents that it is an
"accredited  investor" as that term is defined in rule 501 promulgated under the
Securities Act of 1933, as amended.

         5.  APPOINTMENT  OF  ATTORNEY-IN-FACT.  The Lenders,  other than United
Infrastructure  Company,  LLC,  hereby  appoint,  empower and authorize  Zesiger
Capital  Group,  LLC to act as their  attorney-in-fact  for the sole  purpose of
effecting consents, requests, waivers and amendments under and to this Agreement
and the Loan Documents.




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         6.       Miscellaneous.

                  (a) No Waiver;  Cumulative Remedies. No failure on the part of
the Lenders or the Company to exercise and no delay in exercising, and no course
of dealing with respect to, any right,  power, or privilege under this Agreement
shall operate as a waiver thereof,  nor shall any single or partial  exercise of
any right,  power,  or  privilege  under this  Agreement  preclude  any  further
exercise  thereof or the exercise of any other right,  power, or privilege.  The
rights and  remedies  provided  for in this  Agreement  are  cumulative  and not
exclusive of any rights and remedies provided by law.

                  (b)  Successors and Assigns.  This Agreement  shall be binding
upon  and  inure  to the  benefit  of the  Lenders  and the  Company  and  their
respective heirs, personal representatives,  successors and assigns, except that
the Company may not assign any of its rights or obligations under this Agreement
without the prior written consent of the Lenders.

                  (c) Amendment; Entire Agreement. THIS AGREEMENT, INCLUDING THE
EXHIBITS AND SCHEDULES  ATTACHED  HERETO,  EMBODIES THE FINAL,  ENTIRE AGREEMENT
AMONG  THE  PARTIES  HERETO  AND  SUPERSEDES  ANY  AND  ALL  PRIOR  COMMITMENTS,
AGREEMENTS,  REPRESENTATIONS,  AND  UNDERSTANDINGS,  WHETHER  WRITTEN  OR  ORAL,
RELATING TO THE SUBJECT MATTER HEREOF AND MAY NOT BE  CONTRADICTED  OR VARIED BY
EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OR DISCUSSIONS
OF THE PARTIES HERETO.  THERE ARE NO ORAL  AGREEMENTS  AMONG THE PARTIES HERETO.
The  provisions of this Agreement may be amended or waived only by an instrument
in writing signed by the parties hereto.

                  (d)  Governing  Law;  Severability.  This  Agreement  shall be
enforced,  governed by and construed in accordance with the laws of the State of
New York applicable to agreements made and to be performed  entirely within such
State excepting its choice of law rules, other than Section 5-1401 of New York's
General  Obligation  Law. In the event that any  provision of this  Agreement is
invalid or unenforceable  under any applicable statute or rule of law, then such
provision  shall  be  deemed  inoperative  to the  extent  that it may  conflict
therewith  and shall be deemed  modified to conform with such statute or rule of
law. Any provision hereof which may prove invalid or unenforceable under any law
shall not affect the validity or enforceability of any other provision hereof.

                  (e) Counterparts. This Agreement may be executed in any number
of  counterparts,  each of which shall be deemed an  original,  but all of which
together shall constitute one and the same agreement.

                  (f) Headings.  The headings, captions and arrangements used in
this Agreement are for convenience only and shall not affect the  interpretation
of this Agreement.



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         IN WITNESS  WHEREOF,  the  Company  and the  Lenders  have  caused this
Agreement to be duly executed as of the day and year first above written.


                                            COMPANY:
                                            -------

                                            PROBEX CORP.,
                                            a Delaware corporation


                                            By: /s/ Bruce A. Hall
                                               --------------------------------
                                            Name: Bruce A. Hall
                                            Title: Senior Vice President


                                            LENDERS:

                                            UNITED INFRASTRUCTURE COMPANY, LLC,
                                            a Delaware limited liability company


                                            By:  /s/ Nora A. Blum
                                               --------------------------------
                                                Nora A. Blum
                                                Vice President



                                            THE LENDERS LISTED ON SCHEDULE
                                            B HERETO

                                            By: Zesiger Capital Group, LLC
                                                As agent and attorney-in-fact


                                                By:      ____________________
                                                Name:    ____________________
                                                Title:   ____________________



  EXHIBITS AND SCHEDULES INTENTIONALLY OMITTED.