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


     AGREEMENT  dated as of November  30, 2004 amends and  supercedes  the prior
agreement  dated as of December 1, 2003 ("Prior  Agreement") 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 Three Lincoln Centre, 5430 LBJ Freeway, Suite 1700, Dallas,
Texas 75240.

     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 since January 1, 2001;

     WHEREAS, under the terms of the Prior Agreement, the NL Group (as hereafter
defined)  was not  required  to make a tax  payment  to Valhi in  regard  to the
Section 311 (b) gain, as defined in the Code (as hereafter defined), realized on
the December 8, 2003 distribution (the "Distribution",  as set forth in the NL's
Information  Statement  dated November 10, 2003) of shares of Kronos  Worldwide,
Inc.  ("Kronos"),  or any gain related to subsequent  distributions of shares of
Kronos,  but  only  to  the  extent  such  gains  were  attributable  to  shares
distributed  to members of the Contran Tax Group  (collectively,  the  "Deferred
Intercompany Gain");

     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.

<PAGE>

          (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:  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)  Payment  of  Tax  Related  to  the  Deferred  Intercompany  Gain.
     Notwithstanding anything else in this Agreement to the contrary,  effective
     with the date of this  Agreement,  the NL Group shall be required to make a
     tax payment to Valhi  pursuant to this  agreement in regard to the Deferred
     Intercompany Gain.

     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.

<PAGE>

     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.  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.

<PAGE>

     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 November 30,
2004.

<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