STOCK PURCHASE AGREEMENT


         This Stock  Purchase  Agreement (the  "Agreement")  is made and entered
into as of the 1st day of April, 2005, between Contran  Corporation,  a Delaware
corporation ("Seller"), and Valhi, Inc., a Delaware corporation ("Valhi").

                                    Recitals

         Seller  wishes to sell  2,000,000  shares (the  "Shares") of the common
stock,  $0.01 par value per share, of Valhi owned by Seller, to Valhi, and Valhi
wishes to purchase  the Shares,  on the terms and subject to the  conditions  of
this Agreement (the "Transaction").

                                    Agreement

         The parties agree as follows:

                                   ARTICLE I.
                                 THE TRANSACTION

         Section  1.1.  Purchase  and Sale of  Shares.  Against  payment  of the
purchase  price  therefor as  specified  in Section 1.2,  Seller  hereby  sells,
transfers,  assigns and delivers to Valhi the Shares.  Certificates representing
the Shares are hereby  delivered  accompanied  by stock powers duly  endorsed in
blank.

         Section 1.2. Purchase Price and Payment.  Valhi hereby purchases all of
the Shares for a purchase  price of $17.50 per Share in cash,  payment for which
is hereby made by means of a transfer of  $35,000,000.00 to an account specified
by Seller.

                                   ARTICLE II.
                  REPRESENTATIONS AND WARRANTIES OF THE SELLER

         Seller hereby  represents  and warrants to Valhi as of the date of this
Agreement as follows:

         Section 2.1.  Authority.  It is a corporation  validly  existing and in
good  standing  under  the laws of the state of its  incorporation.  It has full
corporate  power and  authority,  without  the  consent or approval of any other
person, to execute and deliver this Agreement and to consummate the Transaction.
All corporate action required to be taken by or on behalf of it to authorize the
execution, delivery and performance of this Agreement has been duly and properly
taken.

         Section 2.2. Validity. This Agreement is duly executed and delivered by
it and  constitutes  its lawful,  valid and binding  obligation,  enforceable in
accordance with its terms.  The execution and delivery of this Agreement and the
consummation  of the  Transaction by it are not prohibited by, do not violate or
conflict  with any  provision  of, and do not result in a default  under (a) its
charter or bylaws; (b) any material  contract,  agreement or other instrument to
which it is a party or by which it is bound;  (c) any order,  writ,  injunction,
decree or judgment of any court or governmental  agency applicable to it; or (d)
any law,  rule or  regulation  applicable  to it,  except  in each case for such
prohibitions,  violations,  conflicts or defaults that would not have a material
adverse consequence to the Transaction.

         Section 2.3. Ownership of Shares. It is the record and beneficial owner
of the Shares and upon  consummation  of the  transactions  contemplated by this
Agreement,  Valhi will acquire good and marketable title to the Shares, free and
clear of any liens,  encumbrances,  security interests,  restrictive agreements,
claims or imperfections  of any nature  whatsoever,  other than  restrictions on
transfer imposed by applicable securities laws.

                                  ARTICLE III.
                 REPRESENTATIONS AND WARRANTIES OF THE PURCHASER

         Valhi  hereby  represents  and warrants to the Seller as of the date of
this Agreement as follows:

         Section 3.1.  Authority.  It is a corporation  validly  existing and in
good  standing  under the laws of the State of Delaware.  It has full  corporate
power and  authority,  without the consent or approval of any other  person,  to
execute and deliver  this  Agreement  and to  consummate  the  Transaction.  All
corporate  and  other  actions  required  to be taken by or on  behalf  of it to
authorize the  execution,  delivery and  performance of this Agreement have been
duly and properly taken.

         Section 3.2. Validity. This Agreement is duly executed and delivered by
it and  constitutes  its lawful,  valid and binding  obligation,  enforceable in
accordance with its terms.  The execution and delivery of this Agreement and the
consummation  of the  Transaction by it are not prohibited by, do not violate or
conflict  with any  provision  of, and do not result in a default  under (a) its
charter or bylaws; (b) any material  contract,  agreement or other instrument to
which it is a party or by which it is bound;  (c) any order,  writ,  injunction,
decree or judgment of any court or governmental  agency applicable to it; or (d)
any law,  rule or  regulation  applicable  to it,  except  in each case for such
prohibitions,  violations,  conflicts or defaults that would not have a material
adverse consequence to the Transaction.

         Section 3.3. Purchase for Investment.  It is purchasing the Shares sold
and delivered to it hereunder for investment  solely for its own account and not
with a view to, or for resale in connection with, the distribution  thereof.  It
understands that such Shares are restricted  securities under the Securities Act
of 1933, as amended (the  "Securities  Act"),  and that such Shares must be held
indefinitely  unless  they  are  registered  under  the  Securities  Act and any
applicable  state  securities  or  blue  sky  laws  or an  exemption  from  such
registration is available.

         Section 3.4. Nature of Purchaser.  It has such knowledge and experience
in financial and business  matters that it is capable of  evaluating  the merits
and risks of the purchase of the Shares.

                                   ARTICLE IV.
                               GENERAL PROVISIONS

         Section 4.1. Survival.  The representations and warranties set forth in
this   Agreement   shall  survive  the  execution  of  this  Agreement  and  the
consummation of the transactions  contemplated  herein.  The covenants and other
agreements set forth in this Agreement shall terminate on the tenth  anniversary
of this Agreement.

         Section  4.2.  Amendment  and  Waiver.  No  amendment  or waiver of any
provision  of this  Agreement  shall in any event be  effective  unless the same
shall be in a writing  referring  to this  Agreement  and signed by the  parties
hereto,  and then such  amendment,  waiver or consent shall be effective only in
the specific instance and for the specific purpose for which given.

         Section 4.3. Parties and Interest.  This Agreement shall bind and inure
to the  benefit  of  the  parties  named  herein  and  their  respective  heirs,
successors and assigns.

         Section 4.4.  Entire  Transaction.  This Agreement  contains the entire
understanding  among the parties with respect to the  transactions  contemplated
hereby and supersedes all other agreements and understandings  among the parties
with respect to the subject matter of this Agreement.

         Section 4.5.  Applicable  Law. This Agreement  shall be governed by and
construed in accordance with the domestic laws of the State of Delaware, without
giving effect to any choice of law or conflict of law provision or rule (whether
of the  State of  Delaware  or any  other  jurisdiction)  that  would  cause the
application of the laws of any jurisdiction other than the State of Delaware.

         Section 4.6. Severability.  If any provision of this Agreement is found
to violate any statute,  regulation,  rule,  order or decree of any governmental
authority,  court,  agency or exchange,  such invalidity  shall not be deemed to
effect any other  provision  hereof or the  validity  of the  remainder  of this
Agreement  and such  invalid  provision  shall be deemed  deleted to the minimum
extent necessary to cure such violation.

         Section  4.7.  Notice.  All  notices,   requests,   demands  and  other
communications  hereunder shall be in writing and shall be sent by registered or
certified mail, postage prepaid as follows:

         If to the Seller:                  Contran Corporation
                                            5430 LBJ Freeway
                                            Three Lincoln Centre, Suite 1700
                                            Dallas, Texas 75240-2697
                                            Attention:  Secretary

         If to the Purchaser:               Valhi, Inc.
                                            5430 LBJ Freeway
                                            Three Lincoln Centre, Suite 1700
                                            Dallas, Texas 75240-2697
                                            Attention:  General Counsel

         Section 4.8.  Headings.  The sections and other  headings  contained in
this  Agreement are for reference  purposes only and shall not effect in any way
the meaning or interpretation of this Agreement.

         Section 4.9. Expenses.  Except as otherwise  expressly provided herein,
each party to this Agreement  shall pay its own costs and expenses in connection
with the transactions contemplated hereby.

         The parties  hereto have caused this  Agreement to be executed by their
duly authorized officers as of the date first written above.


                                           CONTRAN CORPORATION




                                           By:  /s/ Bobby D. O'Brien
                                                --------------------------------
                                                Bobby D. O'Brien, Vice President


                                           VALHI, INC.




                                           By:   /s/ Steven L. Watson
                                                 -------------------------------
                                                 Steven L. Watson, President