EXHIBIT 10.1

                               LOAN AMENDMENT TO
                             NL INDUSTRIES, INC.
                           RETIREMENT SAVINGS PLAN



      THIS  AGREEMENT  by the  Pension and  Employee  Benefits  Committee  of NL
Industries, Inc.("PEBCO"),

      WHEREAS,  NL Industries,  Inc. ("the Company") has previously  adopted the
Plan known as "NL Industries, Inc. Retirement Savings Plan NL Industries,  Inc."
(the "Plan"); and

      WHEREAS,  pursuant  to  Section  11.2 and 13.1 of the Plan,  PEBCO has the
authority to amend the Plan; and

      NOW, THEREFORE,  the parties hereto agree that the Plan is hereby amended,
effective as of January 1, 2000, or such other date required by any  appropriate
governmental agency, as follows:

      I.  Article X of the Plan is amended by the addition of a new Section 10.7
to read as follows:

      10.7  Loans to Participants

             (a) Who is eligible.  Effective January 1, 2000 loans are permitted
      to any (i)  Participant  or (ii) only to the extent  required by law,  any
      former  Participant,  Beneficiary,  or  alternate  payee under a qualified
      domestic relations order described in Section 414(p) of the Code, who is a
      "party  in  interest,"  as  defined  in  Section  3(14) of the  Act,  or a
      "disqualified  person," as defined in Section  4975(e)(2) of the Code, and
      (iii) on whose behalf an Account or  subaccount  is  maintained  under the
      Plan (hereinafter an individual  described in clause (i) or (ii) and (iii)
      shall be referred to as a "Qualified  Participant").  For purposes of this
      Section, a "loan" shall include any renewal or modification to an existing
      loan   hereunder  so  long  as,  at  the  time  of  any  such  renewal  or
      modification,  the  requirements of this Section are met. Any action taken
      by the  Committee  shall be taken to  establish  or suspend or terminate a
      loan program shall be communicated to Qualified Participants in a time and
      manner   unlikely  to   discriminate   against  any  group  of   Qualified
      Participants.

             (b) How to apply.  A  Qualified  Participant  may  borrow  from his
      vested Account  balance under the Plan,  subject to the provisions of this
      Section and to such  additional  roles or  guidelines as the Committee may
      adopt hereunder, by following the application procedure established by the
      Trustee.  The Qualified  Participant  shall receive written  documents (i)
      specifying  the terms  pursuant to which the requested loan is to be made,
      (ii)  designating the extent,  if any, that the loan will be made from any
      one or more of the investment funds  established under Article VI in which
      the Qualified Participant has an interest, (iii) authorizing the repayment
      of the loan through payroll deductions if the Qualified  Participant is an
      Employee,  or  authorizing a procedure  whereby the Qualified  Participant
      makes


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      repayments if the Qualified Participant is not an Employee, (iv) providing
      such additional  information and documentation as the Committee or Trustee
      shall require,  and (v) including a note and security agreement to be duly
      executed by the  Qualified  Participant,  pursuant to which the  Qualified
      Participant  promises to repay the note and grants a security  interest to
      secure repayment of the loan and the note.

             (c) Loan Procedures.  The Committee shall issue rules or guidelines
      ("Procedures")  which  shall  be  uniformly  applicable  to all  Qualified
      Participants  similarly  situated  and such  guidelines  shall  govern the
      approval  or  disapproval  of  loan  application   requests,  as  well  as
      establishing  terms  governing  loans,  repayments,  defaults,  and  other
      features of the  participant  loan program.  Such Procedures may complete,
      interpret,  and add to the  provision  of this  Section  10.7,  and to the
      extent permitted by law without causing  disqualification of the Plan, may
      contradict and overrule the provision of this Section 10.7.

             (d) Interest  rates and fees. The  Procedures  shall  prescribe the
      manner for  determining  the annual rate of interest to be charged on each
      loan to a  Qualified  Participant  under  the  Plan.  The  annual  rate of
      interest shall provide the Plan with an annual rate of return commensurate
      with the prevailing  interest rate charged on similar  commercial loans by
      persons in the  business  of lending  money for loans  which would be made
      under similar circumstances,  as determined by the Committee. In addition,
      the Procedures  may provide for  assessment of a fee for  processing  loan
      application  forms,  collection and processing late payments,  and similar
      administrative  expenses  which amounts  shall be charged  directly to the
      Account of the affected  Qualified  Participant.  The Committee shall from
      time to time  prescribe  such  additional  Procedures  that it deems to be
      necessary or  appropriate  and which are  consistent  with proper  lending
      practices.

             (e)  Loan  amount  limits.  Whenever  loans  are  permitted,   each
      Qualified  Participant  eligible to take a loan under the Procedures shall
      be entitled to borrow from his Account an amount which is not in excess of
      the lesser of (i) $50,000,  or (ii) one-half (1/2) of the present value of
      the vested Account balance of the Qualified  Participant under the Plan as
      of the most recent  valuation  date.  No  Qualified  Participant  shall be
      entitled to a loan from the Trustee if the amount of the loan is less than
      the minimum  ($1000).  Any  renewal or  modification  of an existing  loan
      hereunder  shall be deemed to be a new loan for purposes of this  Section.
      Any  loan  shall  be  secured  by  up  to  one-half   of  such   Qualified
      Participant's   vested  interest  in  his  Account  balance,  as  measured
      immediately after the origination of each loan hereunder.

      However,   to  the  extent  not  inconsistent  with  the  requirements  of
      applicable provisions of the Code and ERISA, the Committee or the Trustee,
      in their  discretion,  may reduce the maximum  loans allowed to reflect or
      anticipate any potential  fluctuation in the value of plan  investments in
      funds which may be affected by stock market performance. Similarly, if the
      Committee or the Trustee  determines that it is not reasonable or prudent,
      in the  interest  of  Participants  or  Beneficiaries,  to  liquidate  the
      requested  amount from any of the Investment  Funds, the amount to be paid
      to each Qualified Participant who designated that a loan be made from such
      Investment Fund shall be reduced unless the Qualified Participant agrees


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      to that portion of the loan being made from other Investment Funds.

             (f) Number of loans.  Except as may  otherwise be prescribed by the
      Committee in the Procedures, no Qualified Participant shall be entitled to
      originate,  renew or modify more than one loan during any single  calendar
      year, and if a Qualified  Participant who has an outstanding loan requests
      an additional  loan, the entire  outstanding loan shall be repaid before a
      new loan can be processed.

             (g) Repayment schedule and method. Any loan originated,  renewed or
      modified with respect to a Qualified  Participant who is an Employee shall
      be  repaid  by  payroll  deduction  pursuant  to  a  substantially   level
      amortization  schedule  as  provided  in  the  Procedures  issued  by  the
      Committee (with payments not less frequently than quarterly) over the term
      of the loan, or any loan issued  hereunder to a Qualified  Participant who
      is not an Employee  shall be repaid by money order or  certified  check in
      accordance with a substantially level amortization schedule as provided in
      the Procedures (with payments not less frequently than quarterly) over the
      term of the loan. No loan shall have a maturity date in excess of five (5)
      years. Any loan may be prepaid at any time, without penalty, provided that
      the full amount of the loan, plus all interest accrued and unpaid thereon,
      is prepaid at one time.

             (h)  Accounting for loans and  repayments.  Any loan to a Qualified
      Participant hereunder shall be considered to be an earmarked investment of
      the Qualified  Participant's Account. All costs, charges, fees or expenses
      in connection  with  acquisition and disposition of such investment of the
      Qualified   Participant's  Account  shall  be  charged  directly  to  such
      Qualified  Participant's  Account. The amount necessary to pay the loan to
      the Qualified  Participant shall be taken proportionately from each of the
      Investment Funds in which the Qualified Participant's Account is invested,
      unless otherwise  agreed in the loan application or otherwise  provided in
      the  Procedures.  Repayments  of principal and interest on a loan shall be
      made to the Investment Funds in the same proportion as contributions would
      be made pursuant to the Qualified  Participant's then effective investment
      election for new contributions.

             (i) Authority to approve or disapprove loan requests. The Committee
      shall have the  authority  to delegate  the power to review and approve or
      disapprove  loans to such  agents  as the  Committee  shall  deem  proper,
      provided  that any such  agents  shall  act  only in  accordance  with the
      Procedures  established by the Committee  pursuant to this Section, A loan
      may be denied or granted in reduced  amount if the  Committee or its agent
      determines that the Qualified  Participant is not reasonably and prudently
      able to liquidate the necessary amount from any funds in this Account.

             (j) Recordkeeping. The Trustee shall convert all or any part of the
      Qualified  Participant's Account in the aggregate amount necessary to make
      payment of the loan from the Trust Fund to the  extent  designated  in the
      loan  application and shall transfer cash to the Qualified  Participant in
      such aggregate amount.  The Trustee shall maintain  sufficient  records to
      permit an accurate crediting of repayments of the loan.


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             (k) Effect of loans on Participant's  Accounts.  The unpaid balance
      owed by a Qualified  Participant on a loan under the Plan shall not reduce
      the  amount  credited  to him under the  Plan.  However,  from the time of
      payment of the  proceeds  of the loan to the  Qualified  Participant,  his
      Account  balances shall be deemed  invested,  to the extent of such unpaid
      loan  balance,  in such  loan  until the  complete  repayment  thereof  or
      distribution from such Account.  Unless the Procedures provide a different
      ordering,  at the time a loan is made,  the amount  loaned  shall first be
      deemed an  investment  of, and  allocated  to, the  following  sequence of
      sub-accounts,  and for purposes of this Paragraph  where reference is made
      to Basic and Supplemental Pre-Tax  Contributions or Basic and Supplemental
      After-Tax  Contributions,  such terms  shall mean the lesser of the actual
      amount of such unwithdrawn or unloaned contributions or the current market
      value thereof as of the applicable Valuation Date:

                     1.  Basic and  Supplemental  Alter-Tax  Contributions  made
            prior to 1987 to the Predecessor Plan;

                     2.    post-1986    Basic   and    Supplemental    After-Tax
            Contributions, and all or part of the increments earned on all Basic
            and Supplemental After-Tax Contributions made to the Plan and/or the
            Predecessor Plan;

                     3. that  portion of his  account  balance  attributable  to
            Employer Contributions which are fully vested,  including increments
            earned thereon,  made to the Plan and/or the  Predecessor  Plan. For
            purposes of  determining  his vested  percentage at the time of such
            loan,  a  Participant  who has  completed  at least  1,000  Hours of
            Service or six  Months of Service in a calendar  year at the time of
            the loan  shall be  deemed  to have  completed  one year of  Vesting
            Service for that calendar year;

                     4. Employer  Contributions made prior to January 1, 1974 to
            the Predecessor Plan, including increments earned thereon,  Rollover
            Contributions  and direct rollovers from another  qualified trust as
            described  in  subparagraphs  4.10(b) and (c)  including  increments
            thereon;

                     5. Basic and Supplemental  Pre-Tax  Contributions,  made to
            the Plan and/or the Predecessor Plan.

             (l) Effect of loan on withdrawals.  Except for the application of a
      Qualified  Participant's  Account  balance to  repayment  of a loan in the
      event of a default,  no withdrawal may be made by a Qualified  Participant
      of any amount deemed invested in the outstanding balance of a loan.

             (m) Effect of loan on distributions  after  termination of service.
      The  amount  actually  paid in any  distribution  otherwise  payable  to a
      Qualified  Participant  shall be reduced by the amount owed (including any
      accrued interest) on all loans of the Qualified Participant at the time of
      such distribution.  The Trustee shall apply the pledged portion (including
      accrued interest) of the Qualified Participant's Account to be distributed
      or paid toward the


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      liquidation of the Qualified  Participant's  indebtedness  to the Plan and
      the Trustee.  Such reduction shall constitute a complete  discharge of all
      liability  to the Plan and the  Trustee for the loan to the extent of such
      reduction.

             (n) Repayment issues.  All loans under the Plan shall be secured by
      the Qualified  Participant's  vested Account balance;  provided,  however,
      that  repayment  shall be secured by the  Qualified  Participant's  vested
      interest  in his Account  only for such time,  and to the extent  that,  a
      portion of each loan is allocated to such Account.  Unless the  Procedures
      provide a different ordering, any loan repayment amounts shall be credited
      to the Qualified  Participant's  sub-accounts in the following  order, but
      only as reflects the extent to which loan  proceeds were taken from any of
      these sub-accounts:

                     1. Basic and Supplemental  Pre-Tax  Contributions,  made to
            the Plan and/or the Predecessor Plan;

                     2. Employer  Contributions made prior to January 1, 1974 to
            the Predecessor Plan, including increments earned thereon,  Rollover
            Contributions  and direct  rollovers from another  qualified mist as
            described  in  subparagraphs  4.10(b) and (c)  including  increments
            thereon;

                     3. that  portion of his  account  balance  attributable  to
            Employer Contributions which are fully vested,  including increments
            earned thereon, made to the Plan and/or the Predecessor Plan;

                     4.    post-1986    Basic   and    Supplemental    After-Tax
            Contributions, and all or part of the increments earned on all Basic
            and Supplemental After-Tax Contributions made to the Plan and/or the
            Predecessor Plan;

                     5.  Basic and  Supplemental  After-Tax  Contributions  made
            prior to 1987 to the Predecessor Plan.

      If at any time  prior to the full  repayment  of a loan,  the  Participant
      should  cease  to  be a  Participant  by  reason  of  his  termination  of
      employment  for any  reason,  or the Plan  should  terminate,  the  unpaid
      balance  owed by the  Participant  on the loan and all  accrued but unpaid
      interest  shall be due and payable  immediately.  The  Participant  or his
      Beneficiary may make all repayments due on outstanding  loans by certified
      check  or  money  order  within  the  grace  period  provided  for  in the
      Procedures.

      The  Procedures  shall provide for methods of adjusting  payment dates and
      amounts in the event of those  kinds of  approved  leave  without  pay for
      which special repayment rules are authorized or mandated by law.

            (o)  Defaults.  In the  event  of  failure  to make any  payment  of
      principal or interest  under a loan when due, the loan shall be in default
      ("Default")  and all the unpaid balance owed by the Qualified  Participant
      and all accrued but unpaid interest shall be due and


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      payable immediately.  Immediately after the expiration of any grace period
      provided  for in the  Procedures  following  a  Default,  the Plan and the
      Trustee may apply the vested Account balance of the Qualified  Participant
      to pay the loan, in whole or in part,  and take any other action or remedy
      as  allowed  by  law,   provided  that  no   application  of  a  Qualified
      Participant's  vested  Account  balance shall occur prior to the time such
      vested Account balance is otherwise  distributable  under the terms of the
      Plan except as  permitted  by the Code and the Act.  The amount paid under
      any  withdrawal  or  distribution  from the  vested  Account  balance of a
      Qualified  Participant  following a Default shall be reduced by the amount
      of any loan in Default and such amount shall be applied to the unpaid loan
      balance and any accrued but unpaid interest thereon.

        In the event of a default and after the  expiration  of any grace period
provided for in the  Procedures,  any amounts of the defaulted  part of the loan
and to sub-account  eligible for withdrawal  shall be offset against the loan in
order to effect an actual default and immediate distribution.  If some or all of
the loan is attributed to sub-accounts  not eligible for withdrawal,  but assets
are available in sub-accounts eligible for withdrawal, assets of the subaccounts
used for the loan  shall be traded  for  assets  of  sub-accounts  eligible  for
withdrawal on a dollar for dollar basis to the extent necessary to permit offset
and immediate distribution of the loan. To the extent that the loan still cannot
be offset and  immediately  distributed,  the default  shall  result in a deemed
distribution,  but the loan will  remain a debt to the Plan and,  to the  extent
required by law or by the procedures, interest will continue to accrue until the
date the loan is repad or the account is distributed,

      II.  Section  6.1 of the Plan is amended to provide  for a new  investment
fund by the addition or a new subsection (f) to read as follows:

              (f) The Loan Fund,  which shall be maintained for the sole purpose
      of accounting  for the  outstanding  balance of loans to  Participants  in
      accordance  with  Paragraph  10.7.  Provided,   however,  any  loan  to  a
      Participant shall not be considered as an investment in the Loan Fund, but
      instead  shall  be  considered  to  be  an  earmarked  investment  of  the
      Participant's account.

      III.  Article VI of the Plan is further  amended by the  addition of a new
Section 6.10 to read as follows:

                6.11 Loans.  Notwithstanding any other provision of this Article
      VI,  contributions  of a Participant  may,  subject to paragraph  10.7, be
      invested in loans to the Participant.

      IV.  Section  7.4 of the Plan is amended  and  restated to read as follows
(the underlined words indicate the changes):

            7.4 Statement of Participant's Account. As soon as practicable after
the  completion  of a Plan Year,  an  individual  statement of account  shall be
issued to each  Participant  showing the value of his interest in each Fund, and
any loans pursuant to paragraph 10.7.

      V. The first  sentence  of  Section  9.1 (a) of the Plan is amended by the
insertion  of the  words  "(other  than  amounts  invested  in the  Loan  Fund)"
immediately after the words "all vested


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amounts  then  credited  to his  account";  and by the  insertion  of the  words
"including  amounts  invested  in the Loan  Fund"  immediately  after  the words
"exceeds $3,500".

      VI. The third to last  sentence of 'Section 9. l(a) of the Plan is amended
by the insertion of the words "(and the Loan Fund)"  immediately after the words
"NL Stock Fund and the Dresser - Tremont Fund".

      VII.  Section 16.3 of the Plan is amended by the addition of the following
sentence at the end thereof:

      The prohibition  against assignment or alienation of benefits contained in
      this  Paragraph  16.3  shall not apply to any loan to a  Participant  made
      under the Plan if' such loan is  secured by the  Participant's  account in
      the Plan and is exempt from the tax imposed by Section 4975 of the Code by
      reason of Section 4975(d)(a) thereof.

      IN WITNESS  WHEREOF,  on behalf of NL  Industries,  Inc.,  the Pension and
Employee  Benefits  Committee has caused this  Amendment to be executed this 1st
day of December, 1999 to be effective as of January 1, 2000.

                                               PENSION AND EMPLOYEE BENEFITS
                                             COMMITTEE OF NL INDUSTRIES, INC.



                                          By:     /s/ Robert D. Hardy
                                                  ------------------------------

                                          Name:   Robert D. Hardy

                                          Title:  Chairman