AMENDED
                                  TAX AGREEMENT
                                     Between
                                   VALHI, INC.
                                       and
                               NL INDUSTRIES, INC.


          AGREEMENT dated as of December 1, 2003 amends and supercedes the prior
agreement  dated as of  January  1, 2001 by and among  Valhi,  Inc.  ("VHI"),  a
Delaware  corporation  having its principal  executive  offices at Three Lincoln
Centre, 5430 LBJ Freeway,  Suite 1700, Dallas,  Texas 75240, Contran Corporation
("Contran"),  a Delaware  corporation having its principal  executive offices at
Three Lincoln  Centre,  5430 LBJ Freeway,  Suite 1700,  Dallas,  TX 75240 and NL
Industries, Inc. ("NL"), a New Jersey corporation having its principal executive
offices at 16825 Northchase Drive, Suite 1200, Houston, Texas 77060.

          WHEREAS,  VHI and NL are  eligible  to file  consolidated  returns  of
federal income taxes and, subject to certain  jurisdictional  limitations,  have
been  subject to combined  state and local tax  reporting  effective  January 1,
2001;

          WHEREAS, VHI and NL wish to provide for the allocation of liabilities,
and  procedures to be followed,  with respect to federal  income taxes of NL and
any  subsidiaries  of NL and with  respect to certain  combined  state and local
taxes on the terms of this Agreement.

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

1. Definitions. As used in this Agreement, the following terms have the meanings
set forth below:

          (a) Code:  The  Internal  Revenue Code of 1986,  as amended,  and with
     respect to any section thereof any successor  provisions under such Code or
     any successor Code.

          (b) Combined Foreign, State and Local Taxes: For a taxable period, the
     amount of all foreign,  state and local taxes,  together  with all interest
     and penalties with respect thereto,  for which liability is computed (1) on
     the basis of a combined,  unitary or  consolidated  return  (whether at the
     initiative of the tax authority or of the taxpayer) and (2) by reference to
     one or more  members  of the NL Group  and one or more  members  of the VHI
     Group not included in the NL Group.

          (c) Contran  Corporation:  A Delaware  corporation  that is the common
     parent of a group of corporations  electing to file a consolidated  federal
     income tax return.

          (d)  Federal  Taxes:  All  federal  income  taxes,  together  with all
     interest and penalties with respect thereto.

          (e) VHI Group:  VHI and those of its direct and indirect  subsidiaries
     which join in the filing of a  consolidated  federal income tax return with
     its common  parent,  Contran (the  "Contran  Tax Group"),  as such Group is
     constituted  from time to time.  For  purposes  of this  Agreement  (to the
     extent related to Combined Foreign,  State and Local Taxes),  the term "VHI
     Group"  shall  include  all direct and  indirect  subsidiaries  of VHI with
     reference to which Combined Foreign, State and Local Taxes are determined.

          (f) NL  Group:  NL  Industries,  Inc.  and  each  direct  or  indirect
     subsidiary of NL which would be a member of an affiliated group, within the
     meaning of section  1504(a) of the Code, of which NL was the common parent,
     as such  Group is  constituted  from  time to time.  For  purposes  of this
     Agreement  (to the extent  related  to  Combined  Foreign,  State and Local
     Taxes) , the  term  "NL  Group"  shall  include  all  direct  and  indirect
     subsidiaries  of NL with reference to which  Combined,  Foreign,  State and
     Local taxes are determined.

          (g) NL Group Tax Liability:  Except as provided in  subparagraph  (h),
     for a taxable period, the liability for Federal Taxes and Combined Foreign,
     State and Local taxes,  as applicable,  that the NL Group would have had if
     it were not a member of the VHI Group during such taxable period (or during
     any  taxable   period  prior   thereto),   and  instead  filed  a  separate
     consolidated  return for such taxable  period (and during all prior taxable
     periods  beginning after December 31, 2000);  provided,  however,  that for
     purposes  of  determining  such  liability  for a  taxable  period  all tax
     elections  shall be consistent  with the tax elections  made by Contran for
     such  period.  In making such tax  elections it is  understood  the Contran
     Corporation  will make  those tax  elections  which are  beneficial  to the
     Contran Tax Group on a consolidated basis.  Nevertheless,  Contran will use
     its  best  efforts  in  the  case  of  those  elections  which  affect  the
     computation  of  the  NL  Group  Tax  Liability,  to  make  elections  in a
     reasonable manner so as to minimize the NL Group Tax Liability.

          (h) NL Group Tax Liability  Payment  Deferral.  For the taxable period
     ending  December 31, 2003, the NL Group shall not be required to make a tax
     payment to Valhi  pursuant to this  agreement  in regard to the Section 311
     (b) Gain (the "Payment Deferral"),  as defined in the Code, realized on the
     December 8, 2003 distribution of shares of Kronos Worldwide Services,  Inc.
     (the "Distribution",  as set forth in the NL's Information  Statement dated
     November 10,  2003),  but only to the extent such gain is  attributable  to
     shares  distributed  to members  of the  Contran  Tax Group (the  "Deferred
     Intercompany Gain").


          (i)  Deferred  Intercompany  Gain  Recognition.  In  the  event,  NL's
     Deferred  Intercompany  Gain is recognized under the Code, the NL Group Tax
     Liability  shall  include  such  gain in the  taxable  period  in which the
     recognition  event  occurs  for  purposes  of  determined  the NL Group Tax
     Liability.

     2.  Contran as Agent.  Contran  shall be the sole agent for the NL Group in
all matters  relating to the NL Group Tax Liability.  The NL Group shall not (a)
terminate  such agency or (b) without  the consent of Contran,  participate,  or
attempt to  participate,  in any matters  related to the NL Group Tax Liability,
including,  but not  limited  to,  preparation  or filing of, or  resolution  of
disputes,  protests or audits with the Internal Revenue Service,  state or local
taxing  authorities  concerning,  the Contran  Group's  consolidated  returns of
Federal  Taxes,  returns of  Combined  Foreign,  State and Local Taxes or the NL
Group Tax Liability with respect thereto for any taxable period  beginning after
December 31, 2000. The NL Group shall cooperate fully in providing  Contran with
all  information  and  documents  necessary or  desirable  to enable  Contran to
perform its  obligations  under this Section,  including  completion of Internal
Revenue  Service and state or local tax audits in connection  with such NL Group
Tax Liability and  determination  of the proper  liability for such NL Group Tax
Liability.

     3. Liability for Taxes; Refunds.

          (a) VHI, as the common  parent of the NL Group,  shall be  responsible
     for, and shall pay to Contran or a taxing  authority,  as  applicable,  the
     consolidated  tax liability for the VHI Group and has the sole right to any
     refunds received from Contran or a taxing authority, as applicable, subject
     to the provisions of Sections 5 and 6 of this Agreement.

          (b) Notwithstanding any other provision of this Agreement, NL and each
     subsidiary  of NL  which is a member  of the NL  Group  shall be  severally
     liable to VHI for the NL Group Tax Liability.

          (c) NL shall  indemnify  VHI and hold it and the VHI Group  other than
     the NL Group,  harmless from and against any deficiency in the NL Group Tax
     Liability that may be due to VHI.

          (d) VHI shall  indemnify NL and hold it and the NL Group harmless from
     and against any Federal Taxes and Combined  Foreign,  State and Local Taxes
     attributable to the VHI Group or any other member of the Contran Tax Group,
     other than the NL Group, as such taxes are determined  under this and other
     tax sharing agreements.

     4. Tax  Returns.  VHI  shall  file on  behalf  of the NL Group  any and all
federal,  foreign, state and local tax returns that are required as they pertain
to the NL Group Tax Liability. The NL Group, at VHI's request, shall join in any
applicable  consolidated  returns of Federal  Taxes and any  returns of Combined
Foreign,  State and Local  Taxes (for which  returns  have not been  theretofore
filed)  and  execute  its  consent  to each  such  filing  on any form as may be
prescribed  for such consent if such consent is required.  The decision of VHI's
Senior  Vice  President  (or any  other  officer  so  designated  by  VHI)  with
responsibility  for  tax  matters  shall,  subject  to the  provisions  of  this
Agreement, be binding in any dispute between VHI and the NL Group as to what tax
position  should be taken  with  respect  to any item or  transaction  of the NL
Group. The preceding sentence is limited to the tax positions that affect the NL
Group Tax  Liability  and the  combined  VHI Group and  Contran  Tax  Group.  In
addition,  VHI and members of the VHI Group,  including NL and members of the NL
Group,   shall  provide  each  other  with  such  cooperation,   assistance  and
information  as each of them may request of the other with respect to the filing
of any tax return,  amended return,  claim for refund or other document with any
taxing  authority.  NL shall be solely  responsible for all taxes due for the NL
Group with  respect to tax returns  filed by NL or a member of the NL Group that
are required to be filed on a separate company basis, independent of VHI.

     5. Payment of NL Group Tax Liability for Federal  Taxes.  On or before each
date,  as  determined  under  section  6655  of  the  Code,  for  payment  of an
installment of estimated  Federal Taxes,  NL shall pay to VHI an amount equal to
the  installment  which  the NL Group  would  have  been  required  to pay as an
estimated  payment of Federal Taxes to the Internal  Revenue  Service if it were
filing a separate  consolidated  return in respect of the NL Group Tax Liability
(as determined  under  paragraphs  1(g),  1(h), or 1(i)).  Any balance owed with
respect to the NL Group Tax Liability  for such taxable  period shall be paid to
VHI on or before the 15th day of the third month after the close of such taxable
period.  If it is not  possible to  determine  the amount of such  balance on or
before such day, (a) a reasonable  estimate  thereof  shall be paid on or before
such day,  (b) the  amount of such  balance  shall be finally  determined  on or
before the  earlier  of; (i) the 15th day of the ninth  month after the close of
such  taxable  period  and (ii) the date on which the  consolidated  tax  return
containing  the NL Group for such  period  is filed  with the  Internal  Revenue
Service,  and (c) any  difference  between  the  amount  so  determined  and the
estimated  amount paid shall;  (i) in the case of an  underpayment,  be promptly
paid to VHI and (ii) in the case of an  overpayment,  be  promptly  refunded  or
applied  against  the  estimated  NL Group  Tax  Liability  for the  immediately
following tax period, at the option of VHI. If the overpayment is not applied to
the  immediately  following  tax  period,  such  overpayment  shall be  promptly
refunded to the NL Group. As between the parties to this Agreement, the NL Group
shall be solely  responsible  for the NL Group Tax  Liability  and shall have no
responsibility  for Federal  Taxes of the VHI Group or the  Contran  Group other
than payment of the NL Group Tax Liability in accordance  with the terms of this
Agreement.

     6.Refunds for NL Group Losses and Credits for Federal Taxes

          (a) General Provision. If the calculation with respect to the NL Group
     Tax Liability for Federal Taxes results in a net operating loss ("NOL") for
     the current tax period  that,  in the absence of a Code  Section  172(b)(3)
     election made by Contran,  is carried back under Code Sections 172 and 1502
     to a prior taxable  period or periods of the NL Group with respect to which
     the NL Group  previously  made payments to VHI,  then,  in that event,  VHI
     shall pay (or credit) NL an amount  equal to the tax refund to which the NL
     Group  would  have  been  entitled  had  the  NL  Group  filed  a  separate
     consolidated  federal income tax return for such year (but not in excess of
     the net  aggregate  amount of the NL Group Tax  Liability  paid to VHI with
     respect to the  preceding two taxable  periods).  If the  calculation  with
     respect to the NL Group Tax Liability results in an NOL for the current tax
     period,  that  subject  to the  Code  Section  172(b)(3)  election  made by
     Contran,  is not carried  back under Code  Sections 172 and 1502 to a prior
     taxable  period or periods  of the NL Group  with  respect to which NL made
     payments to VHI or is not carried  back  because the Contran Tax Group does
     not have a  consolidated  net  operating  loss for the  current tax period,
     then,  in that  event  such  NOL  shall be an NOL  carryover  to be used in
     computing the NL Group Tax Liability for future taxable periods,  under the
     law  applicable to NOL  carryovers  in general,  as such law applies to the
     relevant  taxable  period.  Furthermore,  if the NL Group  would  have been
     entitled to a refund of Federal Taxes for any year had the NL Group filed a
     separate  consolidated  federal income tax return for the loss year and the
     carryback year, VHI shall pay to NL the amount which NL would have received
     as a refund from the Internal  Revenue  Service.  Payments made pursuant to
     this  Section 6 shall be made on the date that  Contran  (or any  successor
     common  parent of a tax group to which the VHI Group is a member) files its
     consolidated  federal  income tax return for the taxable  period  involved.
     Principles  similar to those discussed in this Section 6 shall apply in the
     case of the  utilization  of all NL Group  loss and credit  carrybacks  and
     carryovers.

          (b) Limitation on NL Group Losses.  Notwithstanding the provisions set
     forth in paragraph 6(a) and in exchange for the Payment Deferral,  NL Group
     Losses  generated in the taxable periods ending after December 31, 2003 may
     not be carried back to the taxable period ending December 31, 2003. NL will
     not be entitled to any refund for the taxable  period  ending  December 31,
     2003,  if such refund is  attributable  to NL Group  Losses  generated in a
     succeeding  taxable  period  regardless  of whether such losses are carried
     back first to a taxable period ending before January 1, 2003.

     7. Payment of NL Group Tax  Liability  for Foreign,  State and Local Taxes.
The  foregoing  principles  contained in Sections 5 and 6 shall apply in similar
fashion to any consolidated or combined foreign, state or other local income tax
returns,  containing  any member of the VHI Group and any member of the NL Group
that is not also a member of the VHI Group, which may be filed.

     8.  Subsequent  Adjustments.  If any settlement  with the Internal  Revenue
Service,  foreign,  state or local tax  authority  or court  decision  which has
become final results in any adjustment to any item of income, deduction, loss or
credit  to the VHI  Group in  respect  of any  taxable  period  subject  to this
Agreement,  which, in any such case,  affects or relates to any member of the NL
Group as  constituted  during such taxable  period,  the NL Tax Group  Liability
shall be  redetermined  to give effect to such adjustment as if it had been made
as  part  of or  reflected  in the  original  computation  of  the NL Tax  Group
Liability and proper adjustment of amounts paid or owing hereunder in respect of
such liability and allocation shall be promptly made in light thereof.

     9.  Amendments.  This  Agreement  may be amended,  modified,  superseded or
cancelled,  and any of the terms, covenants, or conditions hereof may be waived,
only by a  written  instrument  specifically  referring  to this  Agreement  and
executed by both  parties  (or, in the case of a waiver,  by or on behalf of the
party waiving  compliance).  The failure of either party at any time or times to
require performance of any provision of this Agreement shall in no manner affect
the right at a later time to enforce the same.  No waiver by either party of any
condition,  or of  any  breach  of any  term  or  covenant,  contained  in  this
Agreement, in any one or more instances, shall be deemed to be or construed as a
further or continuing waiver of any such condition or breach, or a waiver of any
other condition or of any breach of any other term or covenant.

     10.  Retention of Records.  VHI shall retain all tax returns,  tax reports,
related  workpapers and all schedules  (along with all documents that pertain to
any such tax returns,  reports or workpapers) that relate to a taxable period in
which the NL Group is included  in a  consolidated  or combined  tax return with
VHI. VHI shall make such  documents  available to NL at NL's request.  VHI shall
not dispose of such documents without the permission of NL.

     11.  Headings.  The  headings  of this  Agreement  are for  convenience  of
reference only, and shall not in any way affect the meaning or interpretation of
this Agreement.

     12.  Governing  Law.  This  Agreement  shall be  construed  and enforced in
accordance with the laws of the State of Delaware without regard to conflicts of
laws provisions.

     13. Counterparts.  This Agreement may be executed in multiple counterparts,
each of which shall be an original,  but all of which shall  constitute  but one
agreement.

     14.  Successors.  This  Agreement  shall be  binding  upon and inure to the
benefit of the  parties  hereto  and their  respective  subsidiaries,  and their
respective successors and assigns.

     15.  Effective  Date.  This Agreement  shall be effective as of December 1,
2003.




<PAGE>


     IN WITNESS WHEREOF,  the parties hereto have executed this Agreement on the
date first above written.

                                         VALHI, INC.


                                         By:  /s/ William J. Lindquist
                                              -------------------------------
                                              William J. Lindquist
                                              Senior Vice President




                                         CONTRAN CORPORATION


                                         By:  /s/ William J. Lindquist
                                              -------------------------------
                                              William J. Lindquist
                                              Senior Vice President




                                         NL INDUSTRIES, INC.


                                         By:  /s/ Kelly D. Luttmer
                                              -------------------------------
                                              Kelly D. Luttmer
                                              Tax Director