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                                                                     EXHIBIT 4.4

                           VARCO INTERNATIONAL, INC.

                                THIRD AMENDMENT
                              TO CREDIT AGREEMENT


         This THIRD AMENDMENT TO CREDIT AGREEMENT (this "Amendment") is dated as
of November 7, 1997 and entered into by and among VARCO INTERNATIONAL, INC., a 
California corporation ("Company"), THE FINANCIAL INSTITUTIONS LISTED ON THE 
SIGNATURE PAGES HEREOF (each individually referred to herein as a "Lender" and 
collectively as "Lenders"), and UNION BANK OF CALIFORNIA, N.A. ("UBOC"), as 
agent for Lenders (in such capacity, "Agent"), and is made with reference to 
that certain Credit Agreement dated as of June 27, 1997, as amended by a First 
Amendment to Credit Agreement dated as of July 15, 1997 and by a Second 
Amendment to Credit Agreement dated as of August 13, 1997 (as so amended the 
"Credit Agreement"), by and among Company, Lenders and Agent. Capitalized terms 
used herein without definition shall have the same meanings herein as set forth 
in the Credit Agreement.

                                   RECITALS

         WHEREAS, the parties hereto wish to amend the Credit Agreement in 
certain respects;

         NOW, THEREFORE, in consideration of the premises and the agreements, 
provisions and covenants herein contained, the parties hereto agree as follows:

         Section 1. AMENDMENTS TO THE CREDIT AGREEMENT

         A.    Amendment to Subsection 7.6D. MINIMUM CONSOLIDATED CURRENT RATIO
               ----------------------------------------------------------------

         Subsection 7.6D of the Credit Agreement is hereby amended by deleting 
"2.00 to 1.00" set forth therein and substituting therefor "1.50 to 1.00".

         B.    Amendment to Compliance Certificate
               -----------------------------------

         Exhibit V to the Credit Agreement (Form of Compliance Certificate) is 
hereby amended by deleting "2.00:1.00" in item I.4. of Attachment 1, and 
substituting therefor "1.50:1.00".

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          Section 2. MISCELLANEOUS

          A.     Reference to and Effect on the Credit Agreement and the Other 
                 Loan Documents.

          (i)    Each reference in the Credit Agreement to "this Agreement", 
    "hereunder", "hereof", "herein" or words of like import referring to the
    Credit Agreement, and each reference in the other Loan Documents to the
    "Credit Agreement", "thereunder", "thereof" or words of like import
    referring to the Credit Agreement shall mean and be a reference to this
    Amended Agreement.

          (ii)   Except as specifically amended by this Amendment, the Credit 
    Agreement and the other Loan Documents shall remain in full force and effect
    and are hereby ratified and confirmed.

          (iii)  The execution, delivery and performance of this Amendment shall
    not, except as expressly provided herein, constitute a waiver of any
    provision of, or operate as a waiver of any right, power or remedy of Agent
    or any Lender under, the Credit Agreement or any of the other Loan
    Documents.

          B.     Fees and Expenses. Company acknowledges that all reasonable 
costs, fees and expenses as described in subsection 10.2 of the Credit Agreement
incurred by Agent and its counsel with respect to this Amendment and the 
documents and transactions contemplated hereby shall be for the account of 
Company.

          C.     Headings. Section and subsection headings in this Amendment are
included herein for convenience of reference only and shall not constitute a 
part of this Amendment for any other purpose or be given any substantive effect.

          D.     Applicable Law. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS 
OF THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND 
ENFORCED IN ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF CALIFORNIA 
(INCLUDING WITHOUT LIMITATION SECTION 1646.5 OF THE CIVIL CODE OF THE STATE OF 
CALIFORNIA), WITHOUT REGARD TO CONFLICTS OF LAWS PRINCIPLES.

          E.     Counterparts; Effectiveness. This Amendment may be executed in 
any number of counterparts and by different parties hereto in separate 
counterparts, each of which when so executed and delivered shall be deemed an 
original, but all such counterparts together shall constitute but one and the 
same instrument; signature pages may be detached from multiple separate 
counterparts and attached to a single counterpart so that all signature pages 
are physically attached to the same document. This Amendment shall become 
effective and shall be retroactive to September 30, 1997 upon the execution of a
counterpart hereof by Requisite Lenders and each of the other

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parties hereto and receipt by Company and Agent of written or telephonic 
notification of such execution and authorization of delivery thereof.



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     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be 
duly executed and delivered by their respective officers thereunto duly 
authorized as of the date first written above.

     COMPANY:

                                     VARCO INTERNATIONAL, INC.


                                     By: 
                                         ---------------------------------------
                                     Name:
                                     Title: 

                                     Notice Address:

                                           743 North Eckhoff Street
                                           Orange, CA 92868
                                           Attention: Chief Financial Officer

     LENDERS:

                                     UNION BANK OF CALIFORNIA, N.A.
                                     as a Lender, as Issuing Lender and as Agent

                                
                                     By:
                                        ----------------------------------------
                                     Name:
                                     Title:

                                     Notice Address:

                                           445 South Figueroa Street
                                           16th Floor
                                           Los Angeles, CA 90071
                                           Attention: Andrew G. Ewing, Jr.

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                                     THE CHASE MANHATTAN BANK, as a Lender


                                     By: 
                                         ---------------------------------------
                                     Name:
                                     Title: 

                                     Notice Address:

                                           707 Travis Street, 5th Floor
                                           Houston, TX 77002
                                           Attention: Darl Petty




                                      S-2

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                                     MORGAN GUARANTY TRUST COMPANY OF NEW
                                     YORK, as a Lender


                                     By: 
                                         ---------------------------------------
                                     Name:
                                     Title: 

                                     Notice Address:

                                           60 Wall Street
                                           New York, NY 10260
                                           Attention: Robert Barrett


                                      S-3