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                                                                    EXHIBIT 10.9

                           AMENDMENT TO LOAN AGREEMENT


        THIS AMENDMENT TO LOAN AGREEMENT (this "Amendment") is made and entered
into as of December 31, 1999 by and among NATIONAL-OILWELL, L.P., a Delaware
limited partnership, NATIONAL-OILWELL CANADA LTD., a British Columbia company,
and DRECO ENERGY SERVICES LTD., an Alberta corporation (collectively herein
called the "Borrowers"); each of the Lenders which is or may from time to time
become a party to the Loan Agreement (as defined below) (individually, a
"Lender" and, collectively, the "Lenders"), THE CHASE MANHATTAN BANK OF CANADA,
as "Canadian Agent" ("Canadian Agent"), CHASE BANK OF TEXAS, NATIONAL
ASSOCIATION (previously known as Texas Commerce Bank National Association), as
"U.S. Agent" ("U.S. Agent"), WELLS FARGO BANK (TEXAS), NATIONAL ASSOCIATION, as
U.S. Co-Agent, THE BANK OF NOVA SCOTIA, as Canadian Co-Agent, and
NATIONAL-OILWELL, INC., a Delaware corporation (the "Parent").

                                    RECITALS

        A. The Borrowers, the Lenders, the Canadian Agent and the U.S. Agent
executed and delivered that certain Loan Agreement dated as of September 25,
1997, as amended by instruments dated as of June 1, 1998, June 24, 1998, August
26, 1998, April 1, 1999 and December 20, 1999. Said Loan Agreement, as amended,
supplemented and restated, is herein called the "Loan Agreement". Any
capitalized term used in this Amendment and not otherwise defined shall have the
meaning ascribed to it in the Loan Agreement.

        B. The Borrowers, the Lenders, the Canadian Agent and the U.S. Agent
desire to amend the Loan Agreement in certain respects.

        NOW, THEREFORE, in consideration of the premises and the mutual
agreements, representations and warranties herein set forth, and further good
and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the Borrowers, the Lenders, the Canadian Agent and the U.S. Agent
do hereby agree as follows:

        SECTION 1. Amendment to Loan Agreement. Section 7.3(c) of the Loan
Agreement is hereby amended to read in its entirety as follows:

               (c) Interest Coverage Ratio - an Interest Coverage Ratio of not
        less than (i) for the fiscal quarter ending on December 31, 1999 through
        the fiscal quarter ending on June 30, 2000, 2.00 to 1.00, (ii) for the
        fiscal quarter ending on September 30, 2000, 2.50 to 1.00 and (iii) 3.00
        to 1.00 at all times thereafter.

        SECTION 2. Ratification. Except as expressly amended by this Amendment,
the Loan Agreement and the other Loan Documents shall remain in full force and
effect. Except as expressly provided in this Amendment, (a) none of the rights,
title and interests existing and to exist under the Loan Documents are hereby
released, diminished or impaired, and (b) Parent and the Borrowers hereby
reaffirm all covenants, representations and warranties in the Loan Documents.

        SECTION 3. Expenses. Parent shall pay to the Canadian Agent and the U.S.
Agent all reasonable fees and expenses of their respective legal counsel
(pursuant to Section 11.3 of the Loan Agreement) incurred in connection with the
execution of this Amendment.




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        SECTION 4. Certifications. Each of Parent and the Borrowers hereby
certifies that (a) no material adverse change in its assets, liabilities,
financial condition, business or affairs has occurred and (b) no Default or
Event of Default has occurred and is continuing or will occur as a result of
this Amendment.

        SECTION 5. Miscellaneous. This Amendment (a) shall be binding upon and
inure to the benefit of Parent, the Borrowers, the Lenders, the Canadian Agent
and the U.S. Agent and their respective successors, assigns, receivers and
trustees; (b) may be modified or amended only by a writing signed by the
required parties; (c) shall be governed by and construed in accordance with the
laws of the State of Texas and the United States of America; (d) may be executed
in several counterparts by the parties hereto on separate counterparts, and each
counterpart, when so executed and delivered, shall constitute an original
agreement, and all such separate counterparts shall constitute but one and the
same agreement and (e) together with the other Loan Documents, embodies the
entire agreement and understanding between the parties with respect to the
subject matter hereof and supersedes all prior agreements, consents and
understandings relating to such subject matter. The headings herein shall be
accorded no significance in interpreting this Amendment.

             NOTICE PURSUANT TO TEX. BUS. & COMM. CODE SECTION 26.02

        THE LOAN AGREEMENT, AS AMENDED BY THIS AMENDMENT, AND ALL OTHER LOAN
DOCUMENTS EXECUTED BY ANY OF THE PARTIES PRIOR HERETO OR SUBSTANTIALLY
CONCURRENTLY HEREWITH CONSTITUTE A WRITTEN LOAN AGREEMENT WHICH 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.




        IN WITNESS WHEREOF, the Borrower, the Lenders and the Agent have caused
this Amendment to be signed by their respective duly authorized officers,
effective as of the date first above written.

                                NATIONAL-OILWELL, L.P.,
                                a Delaware limited partnership, as U.S. Borrower

                                By:  Its Sole General Partner, NOW Oilfield
                                     Services, Inc., a Delaware corporation


                                     By:           /s/ Daniel L. Molinaro
                                        ----------------------------------------
                                     Name:         Daniel L. Molinaro
                                          --------------------------------------
                                     Title:        Treasurer
                                           -------------------------------------


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                                NATIONAL-OILWELL CANADA LTD.,
                                a British Columbia company,
                                as Canadian Borrower


                                By:                /s/ Daniel L. Molinaro
                                   ---------------------------------------------
                                Name:              Daniel L. Molinaro
                                     -------------------------------------------
                                Title:             Treasurer
                                      ------------------------------------------



                                DRECO ENERGY SERVICES LTD.,
                                an Alberta corporation, as Canadian Borrower


                                By:                /s/ Daniel L. Molinaro
                                   ---------------------------------------------
                                Name:              Daniel L. Molinaro
                                     -------------------------------------------
                                Title:             Treasurer
                                      ------------------------------------------



                                NATIONAL-OILWELL, INC.,
                                a Delaware corporation, as Parent


                                By:                /s/ Daniel L. Molinaro
                                   ---------------------------------------------
                                Name:              Daniel L. Molinaro
                                     -------------------------------------------
                                Title:             Treasurer
                                      ------------------------------------------



                                CHASE BANK OF TEXAS, NATIONAL
                                ASSOCIATION, as U.S. Agent and as a U.S. Lender


                                By:                /s/ Mona M. Foch
                                   ---------------------------------------------
                                Name:              Mona M. Foch
                                     -------------------------------------------
                                Title:             Managing Director
                                      ------------------------------------------





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                                THE CHASE MANHATTAN BANK OF CANADA,
                                as Canadian Agent and as a Canadian Lender


                                By:                /s/ Christine Chan
                                   ---------------------------------------------
                                Name:              Christine Chan
                                     -------------------------------------------
                                Title:             Vice President
                                      ------------------------------------------

                                WELLS FARGO BANK (TEXAS), NATIONAL
                                ASSOCIATION, as U.S. Co-Agent and as a U.S.
                                Lender


                                By:                /s/ Frank W. Schageman
                                   ---------------------------------------------
                                Name:              Frank W. Schageman
                                     -------------------------------------------
                                Title:             Vice President
                                      ------------------------------------------



                                THE BANK OF NOVA SCOTIA,
                                as Canadian Co-Agent and as a
                                Canadian Lender


                                By:                /s/ J. Doug Foster
                                   ---------------------------------------------
                                Name:              J. Doug Foster
                                     -------------------------------------------
                                Title:             Director
                                      ------------------------------------------




                                THE BANK OF NOVA SCOTIA,
                                as a U.S. Lender


                                By:               /s/ F.C.H. Ashby
                                   ---------------------------------------------
                                Name:             F.C.H. Ashby
                                     -------------------------------------------
                                Title:            Senior Manager Loan Operations
                                      ------------------------------------------



                                THE BANK OF NEW YORK


                                 By:                /s/ Peter W. Keller
                                   ---------------------------------------------
                                 Name:              Peter W. Keller
                                     -------------------------------------------
                                 Title:             Vice President
                                      ------------------------------------------
                                 BANK ONE LOUISIANA, N.A.
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                                 By:                /s/ J. Charles Freel, Jr.
                                    --------------------------------------------
                                 Name:              J. Charles Freel, Jr.
                                      ------------------------------------------
                                 Title:             First Vice President
                                       -----------------------------------------




                                 SOUTHWEST BANK OF TEXAS


                                 By:                /s/ Randall L. Walker
                                    --------------------------------------------
                                 Name:              Randall L. Walker
                                      ------------------------------------------
                                 Title:             Senior Vice President
                                       -----------------------------------------



                                 FIRST UNION NATIONAL BANK


                                 By:                /s/ Robert R. Wetteroff
                                    --------------------------------------------
                                 Name:              Robert R. Wetteroff
                                      ------------------------------------------
                                 Title:             Senior Vice President
                                       -----------------------------------------