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                                                                  EXHIBIT 4.3.16


         THIS WARRANT AND THE SECURITIES ISSUABLE UPON THE EXERCISE HEREOF HAVE
         NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933. THEY MAY NOT BE
         SOLD, OFFERED FOR SALE, PLEDGED, HYPOTHECATED, OR OTHERWISE TRANSFERRED
         EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE
         SECURITIES ACT OF 1933, OR AN OPINION OF COUNSEL SATISFACTORY TO THE
         COMPANY THAT REGISTRATION IS NOT REQUIRED UNDER SUCH ACT OR UNLESS SOLD
         PURSUANT TO RULE 144 UNDER SUCH ACT.



                        WARRANT TO PURCHASE COMMON STOCK
                                       OF
                                  PROBEX CORP.

                          VOID AFTER FEBRUARY 28, 2002


         This Warrant is issued to Bechtel Corporation, or its registered
assigns ("Holder") by Probex Corp., a Colorado corporation (the "Company"), on
February 28, 2000 (the "Warrant Issue Date"). This Warrant is issued in
conjunction with the Wellsville License Agreement (the "License Agreement"), the
Wellsville Plant Process Engineering and Technical Services Agreement (the
"TSA") and the Solvent Finishing Unit Technical Services Agreement (the
"SFUTSA"), each between Holder and the Company. In consideration of the Holder
executing the License Agreement, the TSA, and the SFUTSA and agreeing to defer
the first license fee payment of $273,300 under the License Agreement and 25% of
each invoice under the TSA and the SFUTSA through the earlier of financial close
on the first plant or December 29,2000, up to a maximum of $1,000,000, and in
consideration of the mutual covenants and agreements contained herein, the
Company and the Holder agree as follows:

1. Purchase of Shares. Subject to the terms and conditions hereinafter set
forth, the Holder is entitled, upon surrender of this Warrant at the principal
office of the Company (or at such other place as the Company shall notify the
holder hereof in writing), to purchase from the Company from time to time up to
two hundred thousand (200,000) fully paid and nonassessable shares of Common
Stock of the Company, as constituted on the Warrant Issue Date (the "Common
Stock"). The number of shares of Common Stock issuable pursuant to this Section
1 (the "Shares") shall be subject to adjustment pursuant to Section 7 hereof.

2. Exercise Price. The purchase price for the Shares shall be $3.00 per share,
as adjusted from time to time pursuant to Section 7 hereof (the "Exercise
Price").

3. Exercise Period. This Warrant shall be exercisable, in whole or in part, at
any time within two years after the date hereof. Notwithstanding the term of
this Warrant fixed pursuant to the preceding sentence, the right to purchase
Common Stock as granted herein shall expire, if

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not previously exercised, immediately upon the closing of a merger or
consolidation of the Company with or into another corporation when the Company
is not the surviving corporation, or the sale of all or substantially all of the
Company's properties and assets to any other person, provided that Holder would
have realized in such merger, consolidation or sale a value for its shares, if
it had exercised this Warrant, equal to or greater than three (3) times the
Exercise Price for such shares (the "Threshold") in connection therewith (the
"Termination Event"). The Threshold shall be adjusted in tandem with each
adjustment in the Exercise Price hereunder. In the event of a proposed
transaction of the kind described above, the Company shall notify the holder of
this Warrant at least fifteen (15) days prior to the consummation of such
Termination Event. If such closing does not take place, the Company shall
promptly notify the Holder that the proposed Termination Event has been
terminated and the Holder may rescind any exercise of this Warrant which
occurred after the Company first notified the Holder of the Termination Event.
In the event of such recission, this Warrant will continue to be exercisable on
the same terms and conditions contained herein.

4. Method of Exercise. While this Warrant remains outstanding and exercisable in
accordance with Section 3 above, the Holder may exercise, in whole or in part
from time to time, the purchase rights evidenced hereby. Such exercise shall be
effected by:

(a) the surrender of this Warrant, together with a duly executed copy of the
form of Notice of Exercise attached hereto, to the Secretary of the Company at
its principal offices; and

(b) the payment to the Company of an amount equal to the aggregate Exercise
Price for the number of Shares being purchased, which may be paid by cash,
cashier's check, or wire transfer of immediately available funds, or by the
surrender of promissory notes or other instruments representing indebtedness of
the Company to the Holder.

5. Certificates for Shares. Upon the exercise of the purchase rights evidenced
by this Warrant, one or more certificates for the number of Shares so purchased
shall be issued in the name of the Holder (or as the Holder may direct) as soon
as practicable thereafter (with appropriate restrictive legends, if applicable),
and in any event within ten (10) days of the delivery of the Notice of Election.

6. Representations and Warranties. The Company hereby represents and warrants to
Holder as follows:

(a) Corporate Power. The Company has all requisite legal and corporate power to
execute and deliver this Warrant, to issue the Shares and to carry out and
perform its obligations under the terms of this Warrant.

(b) Authorization. All corporate action on the part of the Company, its
directors and stockholders necessary for the authorization, execution, delivery
and performance of this Warrant by the Company, the authorization, sale,
issuance and delivery of the Shares and the performance of all of the Company's
obligations under this Warrant has been taken. This Warrant, when executed and
delivered by the Company, shall constitute a valid and binding obligation of the
Company enforceable against the Company in accordance with its terms. The Shares
issuable upon exercise of this Warrant have been duly and validly reserved and,
when

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issued in compliance with the provisions of this Warrant, will be validly issued
and will be fully paid and nonassessable and will have the rights, preferences
and privileges described in the Company's Articles of Incorporation, as amended.
The Shares, when issued upon exercise of this Warrant, will be free of any liens
or encumbrances other than those created by or imposed upon the holders thereof
through no action of the Company; provided, however, that the Shares may be
subject to restrictions on transfer under state and/or federal securities laws.
The Common Stock is not subject to any preemptive rights.

7. Adjustment of Exercise Price and Number of Shares. The number of and kind of
securities purchasable upon exercise of this Warrant and the Exercise Price
shall be subject to adjustment from time to time as follows:

(a) Subdivisions, Combinations and Other Issuances. If the Company shall at any
time prior to the expiration of this Warrant subdivide its Common Stock, by
split-up or otherwise, or issue additional shares of its Common Stock as a
dividend with respect to any shares of its Common Stock, the number of Shares
issuable on the exercise of this Warrant shall forthwith be proportionately
increased in the case of a subdivision or stock dividend, or proportionately
decreased in the case of a combination. Appropriate adjustments shall also be
made to the Exercise Price, but the aggregate Exercise Price payable for the
total number of Shares purchasable under this Warrant (as adjusted) shall remain
the same. Any adjustment under this Section 7(a) shall become effective at the
close of business on the date the subdivision or combination becomes effective,
or as of the record date of such dividend, or in the event that no record date
is fixed, upon the making of such dividend.

(b) Reclassification, Reorganization and Consolidation. In case of any
reclassification, capital reorganization, or change in the Common Stock of the
Company (other than as a result of a subdivision, combination, or stock dividend
provided for in Section 7(a) above), then, as a condition of such
reclassification, reorganization, or change, lawful provision shall be made, and
duly executed documents evidencing the same from the Company or its successor
shall be delivered to the Holder, so that the Holder shall have the right at any
time prior to the expiration of this Warrant to purchase, at a total price equal
to that payable upon the exercise of this Warrant, the kind and amount of shares
of stock and other securities and property receivable in connection with such
reclassification, reorganization, or change by a holder of the same number of
shares of Common Stock as were purchasable by the Holder immediately prior to
such reclassification, reorganization, or change. In any such case, appropriate
provisions shall be made with respect to the rights and interest of the Holder
so that the provisions hereof shall thereafter be applicable with respect to any
shares of stock or other securities and property deliverable upon exercise
hereof, and appropriate adjustments shall be made to the Exercise Price payable
hereunder, provided the aggregate Exercise Price shall remain the same.

(c) Adjustment for Capital Reorganization, Merger or Consolidation. In case of
any capital reorganization of the capital stock of the Company (other than a
combination, reclassification, exchange or subdivision of shares otherwise
provided for herein), or any merger or consolidation of the Company with or into
another corporation, whether or not the Company is the surviving corporation, or
the sale of all or substantially all of the assets of the Company other than a
Termination Event as defined in Section 3 hereof, then, and in each such case,
as a part of such reorganization, merger, consolidation, sale or transfer,
lawful provision shall be made so that the

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Holder of this Warrant shall thereafter be entitled to receive upon exercise of
this Warrant, during the period specified herein and upon payment of the
Exercise Price then in effect, the number of shares of stock or other securities
or property of the successor corporation resulting from such reorganization,
merger, consolidation, sale or transfer that the Holder would have been entitled
to if this Warrant had been exercised immediately before such reorganization,
merger, consolidation, sale or transfer, all subject to further adjustment as
provided in this Section 7. The foregoing provisions of this Section 7(c) shall
similarly apply to successive reorganizations, consolidations, mergers, sales
and transfers and to the stock or securities of any other corporation that are
at the time receivable upon the exercise of this Warrant. If the per share
consideration payable to the Holder hereof for shares in connection with any
such transaction is in a form other than cash or marketable securities, then the
value of such consideration shall be determined in good faith by the Company's
Board of Directors. In all events, appropriate adjustment (as determined in good
faith by the Company's Board of Directors) shall be made in the application of
the provisions of this Warrant with respect to the rights and interests of the
Holder after the transaction, to the end that the provisions of this Warrant
shall be applicable after that event to the greatest extent possible.

(d) Notice of Adjustment. When any adjustment is required to be made in the
number or kind of shares purchasable upon exercise of this Warrant, or in the
Exercise Price, the Company shall promptly notify the holder of such event and
(i) of the number of shares of Common Stock or other securities or property
thereafter purchasable upon exercise of this Warrant and (ii) the Exercise Price
after such adjustment.

8. Registration Rights.

(a) Form S-3 Registration. After the date the Company qualifies for the use of
Form S-3, if the Company determines to file a registration statement on Form S-3
or any successor form for the resale of shares of Common Stock for the account
of any selling shareholders, and any Shares are then held by Holders and are not
then included in an effective registration statement, the Company shall promptly
give written notice of such proposed registration to all such Holders and shall
offer such Holders the right to request inclusion of the Shares issued or
issuable upon the exercise of this Warrant. Each Holder shall have thirty (30)
days from the receipt of such notice to deliver to the Company a written request
specifying the number of Shares such Holder intends to sell and the Holder's
intended method of disposition. The Company will use its best efforts to
register under the Securities Act on Form S-3 or any successor form, for public
sale in accordance with the method of disposition specified in such notice, the
number of Shares specified in such notice.

(b) Piggyback Registration.

         (i) Each time that the Company proposes for any reason to register any
of its Common Stock under the Securities Act in connection with the proposed
offer and sale of its Common Stock for money either for its own account or on
behalf of any other security holder ("Proposed Registration"), other than
pursuant to a registration statement on Form S-4, S-8 or any successor thereto,
the Company shall promptly give written notice of such Proposed Registration to
all Holders and shall offer such Holders the right to request inclusion of the
Shares issued or issuable upon the exercise of this Warrant in the Proposed
Registration.

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         (ii) Each Holder shall have thirty (30) days from the receipt of such
notice to deliver to the Company a written request specifying the number of
Shares such Holder intends to sell and the Holder's intended method of
disposition.

         (iii) In the event that the Proposed Registration by the Company is, in
whole or in part, an underwritten public offering, the Company shall so advise
the Holders as part of the written notice given pursuant to Section 8(b)(i), and
any request under Section 8(b)(ii) must specify that the shares of Common Stock
be included in the underwriting on the same terms and conditions as the shares
of Common Stock, if any, otherwise being sold through underwriters under such
registration.

         (iv) Upon receipt of a written request pursuant to Section 8(b)(ii),
the Company shall promptly use its best efforts to cause all such Shares held by
the Holders to be registered under the Securities Act (and included in any
related qualifications under blue sky laws or other compliance), to the extent
required to permit sale or disposition as set forth in the Proposed
Registration.

         (v) In the event that the offering is to be an underwritten offering,
the Holders proposing to distribute their Shares through such underwritten
offering agree to enter into an underwriting agreement with the underwriter or
underwriters selected for such underwriting by the Company.

         (vi) Notwithstanding the foregoing, if in its good faith judgment, the
managing underwriter determines and advises in writing that the inclusion of all
Shares issued or issuable with respect to this Warrant proposed to be included
in the underwritten public offering, together with any other issued and
outstanding shares of Common Stock proposed to be included therein by holders,
other than the Holders (such other shares hereinafter collectively referred to
as the "Other Shares"), would interfere with the successful marketing of such
securities, then the number of such shares to be included in such underwritten
public offering shall be reduced, first from the Other Shares (except only those
Other Shares that have the benefit of any priority rights granted to holders of
certain Other Shares prior to the date of this Warrant), on a pro-rata basis,
based upon the number of Other Shares held by each holder thereof, and only
thereafter, from the number of Shares held by the Holders, on a pro-rata basis;
provided that, in connection with any such public offering, if the managing
underwriter reasonably and in good faith recommends, which recommendation and
supporting reasoning shall be delivered in writing to the stockholders, that no
amount of Other Shares, and Shares held by Holders should be included in the
underwritten public offering, then the Company shall not be required to include
any such shares in such public offering.

9. No Fractional Shares or Scrip. No fractional shares or scrip representing
fractional shares shall be issued upon the exercise of this Warrant, but in lieu
of such fractional shares the Company shall make a cash payment therefor on the
basis of the Exercise Price then in effect.

10. No Stockholder Rights. Prior to exercise of this Warrant, the Holder shall
not be entitled to any rights of a stockholder with respect to the Shares,
including (without limitation) the right to vote such Shares, receive dividends
or other distributions thereon, exercise preemptive rights or be notified of
stockholder meetings, and such holder shall not be entitled to any notice or
other

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communication concerning the business or affairs of the Company. However,
nothing in this Section 10 shall limit the right of the Holder to be provided
the Notices required under this Warrant or the Master Agreement.

11. Transfers of Warrant. Subject to compliance with applicable federal and
state securities laws, this Warrant and all rights hereunder are transferable in
whole or in part by the Holder to any person or entity upon written notice to
the Company. The transfer shall be recorded on the books of the Company upon the
surrender of this Warrant, properly endorsed, to the Company at its principal
offices, and the payment to the Company of all transfer taxes and other
governmental charges imposed on such transfer. In the event of a partial
transfer, the Company shall issue to the holders one or more appropriate new
warrants.

12. Successors and Assigns. The terms and provisions of this Warrant, the
License Agreement and the TSA shall inure to the benefit of, and be binding
upon, the Company and the Holders hereof and their respective successors and
assigns.

13. Amendments and Waivers. Any term of this Warrant may be amended and the
observance of any term of this Warrant may be waived (either generally or in a
particular instance and either retroactively or prospectively), with the written
consent of the Company and the Holder.

14. Reservation of Stock. The Company will at all times reserve and keep
available, solely for the issuance and delivery upon the exercise of this
Warrant, such shares of Common Stock and other stock, securities and property,
as from time to time shall be issuable upon the exercise of this Warrant.


15. Notices. All notices required under this Warrant and shall be deemed to have
been given or made for all purposes (i) upon personal delivery, (ii) upon
confirmation receipt that the communication was successfully sent to the
applicable number if sent by facsimile; (iii) one day after being sent, when
sent by professional overnight courier service, or (iv) five days after posting
when sent by registered or certified mail. Notices to the Company shall be sent
to the principal office of the Company (or at such other place as the Company
shall notify the Holder hereof in writing). Notices to the Holder shall be sent
to the address of the Holder on the books of the Company (or at such other place
as the Holder shall notify the Company hereof in writing).

16. Replacement of Warrants. Upon receipt of evidence reasonably satisfactory to
the Company of the loss, theft, destruction or mutilation of this Warrant and
(in the case of loss, theft or destruction) upon delivery of an indemnity
agreement in an amount reasonably satisfactory to the Company, or (in the case
of mutilation) upon surrender and cancellation of this Warrant, the Company will
issue, in lieu thereof, a new Warrant of like tenor.

17. Attorneys' Fees. If any action of law or equity is necessary to enforce or
interpret the terms of this Warrant, the prevailing party shall be entitled to
its reasonable attorneys' fees, costs and disbursements in addition to any other
relief to which it may be entitled.


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18. Captions. The section and subsection headings of this Warrant are inserted
for convenience only and shall not constitute a part of this Warrant in
construing or interpreting any provision hereof.

19. Governing Law. This Warrant shall be governed by the laws of the State of
Colorado.

         IN WITNESS WHEREOF, Probex Corp. caused this Warrant to be executed by
an officer thereunto duly authorized.

                                          PROBEX CORP.
                                          By: /s/ [ILLEGIBLE]
                                             ----------------------------------
                                             Name
                                             Title

                   ACCEPTED AND AGREED by the undersigned who caused this
Warrant to be executed by an officer thereunto duly authorized to evidence its
receipt hereof and its acknowledgment of its agreements set forth in the
Preamble to this Warrant.

                                          BECHTEL CORPORATION

                                          By: /s/ THOMAS NARDI
                                              ----------------------------------
                                              Name Thomas Nardi
                                              Title Principal Vice President


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                               NOTICE OF EXERCISE

To:  PROBEX CORP.

                   The undersigned hereby elects to purchase ___________________
shares of Common Stock of Probex Corp., pursuant to the terms of the attached
Warrant and payment of the Exercise Price per share required under such Warrant
accompanies this notice.


                   The undersigned hereby represents and warrants that the
undersigned is acquiring such shares for its own account for investment purposes
only, and not for resale or with a view to distribution of such shares or any
part thereof.


                                        WARRANT HOLDER:





                                        By:
                                           -------------------------------------
                                           [NAME]
                               Address:
                                           -------------------------------------

                                           -------------------------------------
Date:
     --------------------

Name in which shares should be registered:

-----------------------------------------