Document:

EXHIBIT 10.1

                                                       Leverkusen, 19 March 1987
                                                       translation Mu/kb/2926jer

                                    Agreement

between
                 Sachtleben Chemie GmbH
                 Pestalozzistrasse 4
                 47198 Duisburg-Homberg

and
                 KRONOS TITAN-GMBH
                 Peschstrasse 5
                 51373 Leverkusen

                 - hereinafter referred to as KRONOS

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Contents

Art. 1     Definitions
Art. 2     Project Description
Art. 3     Construction and Operation of the Waste Acid Reprocessing Plant and
           the Filter Salt Decomposition Plant
Art. 4     Time Schedule for the Construction of the Waste Acid Reprocessing
           Plant
Art. 5     Reprocessing of Leverkusen Waste Acid / Take-over of 70
           % H2SO4 Acid
Art. 6     Decomposition of Filter Salts from Leverkusen
           Waste Acid / Dumping of
           Cinders / Supply of Fresh Acid
Art. 7     Capital Charges for the Waste Acid Reprocessing and Filter Salt
           Decomposition Plants
Art. 8     Operating Costs for the Waste Acid Reprocessing Plant
Art. 9     Costs for the Decomposition of the Leverkusen Filter Salts
Art. 10    Lump-sum Remuneration
Art. 11    Decomposition of Nordenham Filter Salts / Supply of Fresh Acid
Art. 12    Supply of Burner Discharge
Art. 13    Warranty / Liability
Art. 14    Force Majeure
Art. 15    Hardship Clause
Art. 16    Adjustment of the Agreement
Art. 17    Secrecy
Art. 18    Right of Auditing
Art. 19    Transfer of Agreement / Participation of Third Parties
Art. 20    Successor Clause
Art. 21    Taking Effect / Period of the Agreement
Art. 22    Reservations
Art. 23    Other Cooperation
Art. 24    Termination of the Provisional Agreement
Art. 25    Arbitration Clause
Art. 26    Clause on Partial Invaliditiy
Art. 27    Written-Form Clause

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WHEREAS,

KRONOS and Sachtleben, on 18 July 1986 concluded a provisional agreement. This
provisional agreement essentially covers stipulations for the reprocessing of
the waste acid generated in the production of titanium dioxide in the Leverkusen
and Homberg plants, for the decomposition of the filter salts derived from this
waste acid and of further filter salts sent from Nordenham and for the supply of
burner discharge.

THEREFORE, in view of this provisional agreement, the parties now conclude the
following main agreement:

Art. 1 - Definitions

1.    Waste Acid

      Waste acid shall mean the original waste acid as obtained in the form of
      filtrate after Moore filtration in a sulphate process plant. This acid
      contains about 22 per cent sulphuric acid and salts in a range between 5
      and 16 per cent as is customary at Homberg or Leverkusen. An analysis of
      the Homberg and Leverkusen waste acids is shown in Exhibit 1 to this
      Agreement. Potential changes in composition and their effects on the
      reprocessing process, on the filter salt decomposition and on the supply
      of burner discharge shall be agreed on by the parties.
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2.    Filter Salts

2.1   Filter salts derived from Homberg or Leverkusen waste acid shall be the
      residues separated from the waste acid reconcentrated to about 70 per
      cent. They contain varying amounts of adhering acid, depending on the
      process of separation.

2.2   Filter salts from Nordenham are understood to be the centrifuged solids
      from concentrated waste acid (in accordance with the analysis shown in
      Exhibit 2). Potential changes in composition shall be agreed on by the
      parties.

3.    70 % H2SO4 Acid

      After concentration and curing of the waste acid and subsequent separation
      of the filter salts from the filtrate, an acid is obtained that contains
      about 70 per cent H2SO4. It corresponds to the typical analysis shown in
      Exhibit 3 to this Agreement. After start-up of the waste acid reprocessing
      plant this typical analysis will be replaced by a final analysis.

4.    Fresh Acid

      Fresh acid shall mean the sulphuric acid produced in the Homberg sulphuric
      acid plant.

5.    Cinders

      Cinders shall mean the solid residues resulting from the filter salt
      decomposition plant at Homberg. They are generated from pyrites, filter
      salts, coal for the decomposition and/or other additives.
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6.    Burner Discharge

      Burner discharge shall mean the product obtained in the oxidation of
      titanium tetrachloride after wet milling in the form of a slurry. The
      normal product made and processed at present by KRONOS in Leverkusen shall
      be the initial material. Potential changes in composition shall be agreed
      by the parties to this Agreement.

7.    Waste Acid Reprocessing Plant

      The waste acid reprocessing plant shall comprise an evaporation plant to
      concentrate the waste acid to about 70 % H2SO4, a curing station, a filter
      salt separating unit, a coal-fired steam boiler, an oil-fired standby
      boiler as well as all auxiliary equipment required including the necessary
      extension of the infrastructure.

8.    Filter Salt Decomposition Plant

      The filter salt decomposition plant shall mean the Homberg sulphuric acid
      plant converted to decompose filter salt.

9.    Investments

      Investments shall mean all expenditures incurred by Sachtleben directly in
      the construction of the waste acid reprocessing plant and the conversion
      of the sulphuric acid unit for decomposing the filter salts and moreover
      the expenditures liable to be capitalized for the waste acid reprocessing
      plant during the period of the Agreement.

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10.   Capital Charges

      Capital charges shall mean all depreciations incurred by Sachtleben on the
      investments made.

11.   Start-up Costs

      Start-up costs shall mean all costs incurred by Sachtleben until the waste
      acid reprocessing plant starts up operation, which costs do not fall under
      capital charges.

12.   Operating Costs

      Operating costs shall mean all costs incurred by Sachtleben necessary for
      the operation of the waste acid reprocessing plant or immediately
      resulting from its operation. Breakdown of overheads shall follow the
      principles commonly applied by Sachtleben.

13.   Filter Salt Quantities

13.1  Basic Quantities

      The term basic quantities - derived from planning data - shall mean the
      quantities resulting from the multiplication of 242 kg filter salt/m.t.
      waste acid multiplied by waste acid quantity.

      1000 kg filter salt weighed as a filter cake after discharge from the
      separating facilities contain:

      600 kg MESO4 (anhydrous)
      210 kg H2SO4 (100 %) and
      190 kg H2O

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      As the percentage of adhering acid and water may vary as a function of the
      separating machinery and the composition of the filter salts, resulting in
      different quantities of filter salts, the 'basic quantity' shall be
      calculated from the waste acid analysis. For the purpose of this
      calculation, a content of 145 kg MESO4 (anhydrous) per metric ton of waste
      acid is equated with 242 kg filter salt tel quel.

13.2  Additional Quantities

      The Nordenham filter salts and all quantities exceeding 13.1 shall mean
      additional quantities. For Nordenham filter salt, the incoming quantities
      weighed shall be applicable. Additional quantities of Leverkusen waste
      acid may be involved if the analysed content of anhydrous salts exceeds
      145 kg MESO4/m.t. waste acid. This additional quantity shall be determined
      by multiplying the difference between actual content of anhydrous salts
      per kg/t and 145 kg/t waste acid at first by factor 1.67 and then by the
      quantity of waste acid. The content of anhydrous salt required for the
      calculation shall be determined in accordance with Exhibit 4, "Analyses".

14.   Terms of Delivery

      All deliveries provided for in this Agreement shall be distributed evenly
      over the year.

      Logistics in detail shall be agreed on by the parties, taking into account
      the interests of both parties as well as the requirements of the supplying
      plants.

      The terms of delivery for each individual product are stipulated in
      Exhibit 5 to this Agreement.

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15.   Waste Disposal / Dumping

      Waste disposal and/or dumping shall mean the transportation (including
      loading and unloading) of cinders, potential interim storage or cinders
      (once or several times) and the final depositing of the cinders.

16.   Subsidies / Allowances

      Subsidies and allowances shall mean nonrepayable government grants in the
      form of monies for the construction of the waste acid reprocessing plant
      or for the conversion of the sulphuric acid plant to decompose filter
      salts.

Art.  2 - Project Description

1.    Sachtleben shall build and operate a waste acid reprocessing plant to
      reprocess the waste acid generated in the production of titanium dioxide
      by the sulphate route. Sachtleben and KRONOS agree to dimension the
      capacity of this plant such to permit Sachtleben to perform the work
      assumed in Paragraph 2:

2.    Sachtleben undertakes to concentrate the waste acid generated in the
      Leverkusen plant of KRONOS together with Sachtleben's own waste acid, to
      roast and decompose the filter salts by-produced in this concentration as
      well as the filter salts by-produced in the Nordenham plant, and to
      deposit the resulting cinders or to utilize them in another way.

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      KRONOS shall take the resulting 70 % H2SO4 acid free of charge and shall
      buy from Sachtleben the sulphur content of the filter salts (Leverkusen
      and Nordenham) in the form of fresh acid.

3. KRONOS shall sell Sachtleben burner discharge.

Art. 3 - Construction and Operation of the Waste Acid Reprocessing Plant and
         the Filter Salt Decomposition Plant

1.    Engineering and construction of the waste acid reprocessing and the filter
      salt  decomposition  plant shall be incumbent on Sachtleben.  Furthermore,
      Sachtleben  shall be solely  responsible  for operating these plants after
      completion in accordance  with its  customary  rules of operation.  KRONOS
      shall support Sachtleben in the engineering, construction and operation of
      these  plants and, on request,  shall make  available  to  Sachtleben  its
      knowledge  and  experiences  in the  reprocessing  of waste acid as far as
      agreements  with third  parties do not prevent  KRONOS from  passing  such
      knowledge and experiences.

2.    In accordance with the stipulations of this Agreement, KRONOS shall make
      payments to Sachtleben that are determined from the capital charges,
      start-up and operating costs. The start-up and operating costs to be borne
      by KRONOS shall be paid by KRONOS after they have been incurred and
      calculated monthly by Sachtleben. KRONOS shall pay Sachtleben advances on
      the capital charges to be borne by KRONOS and shall make these advances
      available to Sachtleben on Sachtleben's request with progressing
      construction. These advances shall be independent of the period of the
      Agreement and not repayable.

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      Moreover, KRONOS shall pay Sachtleben a lump-sum remuneration in
      compliance with the stipulations of this Agreement.

Art.  4 - Time Schedule for the Construction of the Waste Acid Reprocessing
          Plant

      Sachtleben and KRONOS both have to comply with conditions imposed by the
      authorities according to which ocean dumping of waste acid must be ceased
      by the end of 1989. Sachtleben shall therefore take all reasonable steps -
      also in its own interest - to complete construction and start up operation
      of the waste acid reprocessing plant possibly by 31 December 1988, however
      without guaranteeing completion by this date.

Art.  5 - Reprocessing of Leverkusen Waste Acid / Take-over of 70 % H2SO4 Acid

1.    After completion of the waste acid reprocessing plant, Sachtleben shall
      reprocess in it the waste acid obtained at the KRONOS plant in Leverkusen
      in the TiO2-production by the sulphate route, the quantity amounting to
      about 220,000 t + 10,000 t annually. In case Sachtleben is not able to
      handle these quantities, Sachtleben shall inform KRONOS immediately in
      order that acceptable technical steps can be taken to solve the problem.

2.    KRONOS shall take from the Homberg plant, without charge, 80 % of the free
      acid contained in the waste acid delivered, in the form of 70 % H2SO4
      acid. The content of free acid in the waste acid, which is required for
      the calculation, shall be determined according to Exhibit 4 "Analyses".

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      In addition, Sachtleben is ready to supply KRONOS with up to 6,000 TPY 70
      % H2SO4 acid at a special price.

      In case Sachtleben is not able to concentrate the acid to 70 % according
      to the typical analysis of Exhibit 3, Sachtleben shall inform KRONOS
      immediately in order that acceptable technical steps can be taken to solve
      the problem.

3.    The  parties  agree that  KRONOS is  co-owner  of the waste acid stored at
      Sachtleben,  of the 70 %  H2SO4  acid  and  of  any  intermediate  product
      generated  within  the  scope  of  the  transformation.   The  rights  and
      obligations  resulting  from its rate of  ownership/co-ownership  shall be
      independent of the obligations assumed by Sachtleben under this Agreement.
      The percentage of KRONOS'  ownership is calculated  from the ratio between
      the waste acid supplied by KRONOS and that of Sachtleben  and of potential
      third parties.  KRONOS shall share  liabilities and risks for the products
      mentioned at the ratio of its co-ownership  beyond the termination of this
      Agreement.

Art. 6 - Decomposition of Filter Salts from Leverkusen Waste Acid / Dumping of
         Cinders / Supply of Fresh Acid

1.    In its filter salt decomposition plant, Sachtleben shall decompose for
      KRONOS the filter salts obtained in reprocessing the Leverkusen waste acid
      together with its own filter salts and filter salts supplied by KRONOS.
      Sachtleben shall use pyrite and/or coal in this decomposition and shall
      dump the cinders by-produced as far as possible under reasonable
      conditions.

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2.    The parties agree that KRONOS shall obtain a co-ownership in the cinders
      by-produced according to Art. 6, Para 1 viz. at a ratio of the filter salt
      quantities decomposed for KRONOS to the filter salt quantities decomposed
      for Sachtleben. The rights and obligations resulting from the ownership
      co-ownership shall be independent of the obligations assumed by Sachtleben
      under this Agreement. KRONOS shall share liabilities and risks for the
      cinders generated at the ratio of its co-ownership beyond the termination
      of this Agreement.

3.    The costs (status mid-1985) incurred in dumping the cinders are included
      in the cost formula for basic and additional quantities. Sachtleben
      assumes all cinders can be dumped in the same way as at present.

      KRONOS, however, knows that intermediate storage of the cinders may become
      necessary in future.

      Costs for further intermediate storage or final depositing will be shared
      by KRONOS and Sachtleben at the ratio of their originally agreed
      ownerships in the cinders. KRONOS shall pay its share in the costs
      immediately after they have been incurred and calculated as far as these
      costs were not yet settled according to the formula for basic and
      additional quantities.

      KRONOS's cost sharing for cinder disposal shall not be affected by a
      potential termination of the Agreement.

      Sachtleben shall inform KRONOS about essential developments regarding
      dumping of the cinders.

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Art. 7 - Capital Charges for the Waste Acid Reprocessing and Filter Salt
         Decomposition Plants

1.    KRONOS shall share the capital charges for the waste acid reprocessing
      plant. They are calculated from the total capacity of the waste acid
      reprocessing plant of about 780,000 TPY split up between KRONOS and
      Sachtleben within the scope of "quantities reserved". The term "quantities
      reserved" shall mean that about 230,000 TPY are apportioned to KRONOS and
      about 550,000 TPY to Sachtleben. The capital charges for the waste acid
      reprocessing plant shall therefore be borne by the parties at a ratio of
      30 % KRONOS and 70 % Sachtleben.

2.    The capital charges for the modification of the filter salt decomposition
      plant shall likewise be shared by the parties at a ratio of 30 % KRONOS
      and 70 % Sachtleben.

3.    The level of investments for the construction of the waste acid
      reprocessing plant and for the filter salt decomposition plant is
      estimated by both parties to be about DM 125 million (price basis and
      state of knowledge mid-1985). This amount comprises a high-concentration
      plant for concentrating the 70 % acid to 78 % H2SO4 acid, this plant being
      utilized by Sachtleben alone. Expenditures for this unit were estimated to
      amount to DM 5 million (price basis and state of knowledge mid-1985).

      According to the estimate of mid-1985, about DM 120 million less expected
      subsidies / allowances of 15 per cent thus have to be shared by the
      parties at a ratio of 30 % KRONOS to 70 % Sachtleben. According to the
      1985 estimate, KRONOS would have to bear capital charges of DM 30.6
      million.

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4.    All investments shall be laid open.

5.    In case one of the parties obtains further subsidies for the investments
      during the period of the Agreement, these subsidies shall also be made
      available for this project.

6.    In case subsidies or allowances granted to Sachtleben during the period of
      the Agreement are partly or wholly reclaimed, KRONOS shall immediately pay
      Sachtleben 30 % of the amount reclaimed taking into account the principles
      outlined under Paragraph 7.

7.    In case only one party benefits from investments solely or at a ratio of
      utilization other than 30 : 70 (for example the high-concentration plant
      of which only Sachtleben takes advantages or the waste acid unloading
      station from which only KRONOS derives benefit), the resulting capital
      charges shall be borne by the respective party either alone or in
      proportion to the ratio of utilization.

8.    In case the initial  expenditures as estimated under 3. above are exceeded
      by more than 15 per cent in the more precise investment  estimate (planned
      capital  expenditures  prior to beginning  building),  both parties  shall
      newly discuss the  situation  with the objective not to exceed the planned
      net expenditures. In case the parties do not come to an agreement on these
      expenditures,  each  party  shall  have  the  right to  withdraw  from the
      contract  to  the  extent  that  the  waste  acid  reprocessing  plant  is
      concerned.  In this  case,  the  expenditures  made  till  then  shall  be
      apportioned and refunded to the parties in accordance with this Agreement.

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Art.  8 - Operating Costs for the Waste Acid Reprocessing Plant

1.    Like the capital charges, the fixed costs for the operation of the waste
      acid reprocessing plant shall be split up among the parties at a ratio of
      30 % KRONOS and 70 % Sachtleben. The variable operating costs shall be
      apportioned in proportion to the waste acid quantities reprocessed. The
      fixed and variable operating costs as well as the modes of payment and
      accounting are explained in more detail in Exhibit 6.

2.    The fixed costs shall be borne for the total period of the Agreement and
      also in case of force majeure. In case KRONOS is no longer able to supply
      waste acid, Sachtleben shall try to reduce the fixed costs. KRONOS shall
      be authorised to pay-off the fixed costs in a one-time payment provided
      the parties agree on a pay-off amount.

3.    The operating costs, excluding depreciations and interest for fixed
      assets, were estimated to total DM 22 million/year (price basis and state
      of knowledge mid-1985).

      Based on the above estimate, the share in operating costs to be paid by
      KRONOS would be (assuming KRONOS takes its share of 70 % H2SO4 acid free
      of charge):

      a) Performance cost (fixed operating cost) per year DM 3.5 million

      b) Labour cost (variable operating cost) DM 3 million based on an
         estimated tonnage price of DM 13/t of waste acid and a supply of
         230,000 TPY waste acid per year

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4.    In  case  the  operating  costs  as  estimated  before  the  beginning  of
      construction exceed the operating costs as estimated under 3. by more than
      20 per cent,  the parties  shall come to an agreement on the new situation
      before starting construction, with the objective not to exceed the planned
      operating  costs. In case the parties do not come to an agreement on these
      costs,  each party shall have the right to withdraw from this Agreement as
      far as the waste acid reprocessing  plant is concerned.  In this case, the
      non-operating  costs incurred so far shall be apportioned  and refunded to
      the parties pursuant to this Agreement.

5.    The start-up costs incurred during the construction of the waste acid
      reprocessing plant shall likewise be borne by the parties at a ratio of 30
      % KRONOS and 70 % Sachtleben. They shall be laid open and settled when
      incurred.

Art.  9 - Cost for the Decomposition of the Leverkusen Filter Salts

1.    The costs of decomposing the filter salts derived from the Leverkusen
      waste acid shall be calculated from the following equation for the basic
      quantities:

      PFSB = F + 2.82 x PP + 2.32 x PA - 4.58 x PS - 1.77 x PE
      (DM/t filter salt)

      F = FO (0.3 L/LO + 0.7)

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      Wherein:

      PFSB     =  Price charged for basic quantities of filter salt (DM/t)

      PP       =  Sachtleben cost price for pyrite, 48 % S (DM/t)

      PA       =  Costs for dumping of cinders (DM/t)

      PS       =  Proceeds from sale ex works of acid to third parties (DM/t)

      PE       =  Price to be charged for waste heat from roasting (DM/t)

      F        =  Basic charge (DM/t filter salt)

      L        =  Wages according to Sachtleben's wage statistics

      Lo       =  Wages according to Sachtleben's wage statistics.
                  Status: monthly average of July 1985

      In mid-1985, the value for PFSB was zero.

      As far as PFSB will rise by DM 50/t in comparison with the basis
      (mid-1985: PFSB = 0), both parties shall take reasonable steps to reduce
      PFSB.

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2.    For additional quantities, the costs for decomposing filter salts derived
      from the Leverkusen waste acid shall be calculated as follows:

      PFSZ = G + 1.52 x PC + 0.4 x PA - 0.55 x PS - 0.51 x PE
      (DM/t filter salt)

      G = GO (0.3 L/LO + 0.7)

      Wherein:

      PFSZ     =  Price charged for additional quantities of filter salt (DM/t)

      G        =  Basic charge (DM/t filter salt)

      PC       =  Cost price for coal for the decomposition (DM/Gcal)

      PA       =  Costs form cumping of cinders (DM/t)

      PS       =  Proceeds for sale ex works of acid to third parties (DM/t)

      PE       =  Credit for waste heat from roasting/decomposition (DM/Gcal)

      L        =  Wages according to Sachtleben's wage statistics

      Lo       =  Wages according to Sachtleben's wage statistics.
                  Status: monthly average of July 1985

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      In mid-1985, the value for PFSZ was DM 90/t filter salt free pyrite
      warehouse of the Homberg sulphuric acid plant.

3.    All technical factors of the cost formulas given under Paragraphs 1 and 2
      above shall be adjusted currently when operating data are available.

      In case the cost-of-living index pursuant to Art. 10, Paragraph 2
      essentially deviates from the average of 1985, the parties shall discuss
      an adjustment of the non-indexed portion of the price formulas listed in
      Art. 9, Paragraphs 1 and 2.

4.    The prices to be charged for the filter salt quantities pursuant to Art.
      9, Paragraphs 1 and 2 will be calculated monthly. The figures applicable
      for the month of delivery are those of the previous month. Accounting is
      done monthly.

5.    The prices calculated by Sachtleben may be checked by KRONOS in compliance
      with Art. 18.

Art.  10 - Lump-sum Remuneration

1.    In addition to the share in capital charges and operating costs, KRONOS
      shall pay Sachtleben an annual lump-sum of DM 3 million, payable in
      monthly installments beginning at the start-up of the waste acid
      reprocessing plant, for the reprocessing of the waste acid and the
      decomposition of the Leverkusen filter salts.

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2.    In case the cost-of-living index (the price index for the cost of living
      of all private households, series 17, line 7), as officially ascertained
      for the entire Federal Republic of Germany by the Statistical Federal
      Offices in Wiesbaden, goes up or down in comparison with the 1985 average
      (= 121.0 on the basis of 1980 = 100), the lump sum payment shall change
      accordingly on a percentage basis beginning with the month that follows
      the month of publication for the period until the next index is published,
      as a rule for one year.

Art.  11 - Decomposition of Nordenham Filter Salts / Supply of Fresh Acid

1.    At the Nordenham plant of KRONOS, filter salts are obtained in the
      concentration of waste acid. Sachtleben shall decompose these filter salts
      for KRONOS either solely or together with the filter salts derived from
      Sachtleben's own waste acid and/or from the waste acid supplied by KRONOS.
      For the decomposition Sachtleben shall use pyrite and/or coal and shall
      dump the cinders obtained.

2.    Beginning roughly in mid-1987, KRONOS shall supply Sachtleben with an
      annual quantity of about 25,000 t filter salt. Once the Nordenham waste
      acid reprocessing plant is in full operation, the quantity of filter salt
      to be taken over by Sachtleben shall be raised to 50,000 TPY.

3.    The remuneration for the decomposition of these filter salts shall be
      calculated by means of the formula for the additional quantities given in
      Art. 9, Paragraph 2. The amount thus calculated in mid-1985 was DM 90/t
      filter salt free pyrite warehouse of the Homberg sulphuric acid plant.

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4.    The costs for dumping the cinders (basis mid-1985) are included in the
      formula for additional quantities. Sachtleben assumes that all cinders can
      continue to be deposited in the same way as at present. As for the rest
      Art. 6, Para. 2 of this Agreement shall apply.

5.    Art. 6, Paragraph 2 of this Agreement shall apply with regard to
      ownership, apportionment of liability and risk.

6.    Sachtleben shall supply KRONOS with fresh acid which corresponds to the
      sulphur content of the filter salts delivered by KRONOS. For each ton of
      filter salt delivered, KRONOS shall take continuously 0.63 t fresh acid
      (100 %) in the form of 96 % fresh acid. On 1 July 1985, the price to be
      paid by KRONOS for the 96 % fresh acid was DM 85 for 100 % fresh acid ex
      Homberg plant. The price will change in accordance by Sachtleben for sales
      of 96 % fresh acid to third parties ex Homberg works.

7.    Since the  decomposition  of filter salts derived from the Nordenham plant
      shall begin already  prior to the start-up of the waste acid  reprocessing
      plant and since the conditions  for this  decomposition  are  economically
      related to the construction  and operation of the waste acid  reprocessing
      plant,  both  parties  undertake  to  discuss a new the  decomposition  of
      Nordenham  filter  salts  in case  the  project  of the  construction  and

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      operation  of  said  plant  fails.  This  however  shall  not  touch  upon
      Sachtleben's  obligation  to decompose  the filter salt from the Nordenham
      plant.  As far as conditions  have to be newly  stipulated,  this shall be
      done with  reasonable  disclosure  of the changed  situation in order that
      Sachtleben  obtains  payment  for  the  costs  incurred  and  an  adequate
      remuneration.

Art.  12 - Supply of Burner Discharge

1.    In exchange for the services rendered by Sachtleben under this Agreement,
      KRONOS shall supply Sachtleben with up to 20,000 TPY burner discharge in
      compliance with the following stipulations/options.

2.    From mid-1988, KRONOS shall sell Sachtleben a quantity of 5,000 m.t.
      burner discharge annually. Sachtleben shall take over this quantity at
      intervals to be agreed on.

3.    Moreover, Sachtleben shall be granted a purchase option for further
      quantities up to another 5,000 m.t. per year (option quantity 1). Each
      option has to be exercised by 30 June of the year preceding the year of
      delivery, for the first time by 30 June 1987. Sachtleben shall be bound to
      take the quantity opted for at the intervals agreed on.

      The option can be exercised for only 30 %/year of the option quantity of
      5,000 m.t. The same applies if Sachtleben desires to opt for differing
      quantities in subsequent years. The opted quantities can be called off
      only in steps of 30 % per year.

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4.    For the purpose of burner  discharge sale and grant op the option,  KRONOS
      assumes that in addition to the Leverkusen  plants of a capacity of 80,000
      TPY, the  Varennes  plant in Canada will have gone on stream by the end of
      1988 and will have achieved a capacity (nominal) ob 40,000 TPY. In case it
      is foreseeable  that these  capacities will not be attained,  KRONOS shall
      take  reasonable  technical  steps to attain the total capacity of 120,000
      TPY. If, nevertheless,  the total capacity cannot be reached by the end of
      1988,  KRONOS shall be authorized to reduce the sale and option quantities
      of 5,000  m.t.  each in  percent  proportionately  to the  total  capacity
      deficiency.  In case KRONOS or the plant in Varennes/Canada is no longer a
      member of the NL group, a potential  reduction of the quantities will take
      into  account  only the  total  capacity  of the  Leverkusen  plants.  The
      quantity  deficiencies  for  each  subsequent  year  of  delivery  will be
      determined in July after the production  figures for the first half of the
      calendar year are available; for the first time they will be determined in
      July 1989 for the delivery year 1 July 1989 - 30 June 1990.

      If, contrary to expectations, completion of the plant in Varennes is
      delayed, KRONOS shall inform Sachtleben in due course. In this case, both
      parties shall come to an agreement on a new date for the beginning of
      delivery.

<PAGE>
                                     - 24 -

5.    Sachtleben shall be granted a further purchase option for up to 10,000
      m.t. burner discharge per year (option quantity 2). The condition,
      however, is that additional chloride process plants of the present
      standard size of 40,000 TPY (excluding substitutions for existing sulphate
      process plants) be built either by KRONOS or NL Industries, Inc. or NL
      Chemicals Inc.

      This option can be exercised only in steps (upward or downward) of up to
      40 % per year (4,000 TPY).

      The conditions or making available option quantity 2 shall be stipulated
      by both parties on start-up of additional plants fully owned by KRONOS, NL
      Chemicals Inc. or NL Industries, Inc. If plants are built in which KRONOS
      does not have a 100 % interest but only a majority interest, a decision
      shall be taken in each case on whether an option can be granted and
      exercised.

6.    The price payable by Sachtleben to KRONOS for the burner discharge (5,000
      t and 5,000 t option quantity 1) shall be calculated as follows:

      a) Manufacturing costs incurred by KRONOS for Leverkusen burner discharge
         according to the key commonly used by KRONOS plus/minus

      b) 50 % of the difference between the net proceeds and the manufacturing
         cost incurred by KRONOS for CP pigments according to the keys commonly
         used by KRONOS calculated on the basis of "ex works" Leverkusen. If

<PAGE>

                                     - 25 -

         delivery is effected ex Langerbrugge plant, Sachtleben shall bear 50 %
         of the additional freight (at present about 50 % above freight ex
         Leverkusen). Deliveries by KRONOS to associated companies shall not be
         included in the calculation of net proceeds.

         The price thus calculated in April 1986 for burner discharge ex
         Leverkusen plant was DM 2,840 per tonne.

         The sales price in DM/tonne for burner discharge ex Leverkusen plant
         shall be altered according to the following formula:

         Pi       = Po [0.36 Ti/To + 0.20 Li/Lo
                        + 0.07 Ei/EO + 0.37 x Il/Io
                        + 0.5 [net proceeds - HK I- HK I ]

         Wherein:

         Pi      sales price for burner discharge ex Leverkusen in DM/m.t. in
                 the period i.

         Po      manufacturing costs for burner discharge in Leverkusen in April
                 1986 (DM 2,400/m.t.).

         Ti/To   ratio of the prices for titaniferous raw materials in the
                 period i/in April 1986.

<PAGE>
                                     - 26 -

         Li/Lo   ratio of negotiated wages per hour for wage class 4, above 18
                 years of age, normal shift (Collective Agreement for Hourly and
                 Salaried Employees and Apprentices of the Chemical Industry in
                 the Counties Dusseldorf and Cologne) in the period i/in April
                 1986 (DM 13.07/h).

         Ei/Eo   ratio of the Dusseldorf prices (stated by the Federal
                 Statistical Office) for fuel oil S, normal quality, arithmetic
                 mean value of the three quantity scales (series 17, line 2) for
                 the period i/April 1986 (DM 254.34/m.t.).

         Ti/To   ratio of the cost-of-living index pursuant to Art. 10,
                 Paragraph 2 during the period i/in April 1986 (= 120.9 on the
                 basis of 1980).

         In case the values are no longer published, the parties shall agree on
         new values that come as close as possible to the old reference values.

         With the exception of the wages, the prices shall be adjusted on 1
         April and 1 October of each year. On 1 April, the adjustment shall be
         based on the average values of the second half of the previous calendar
         year; on 1 Oct, it shall be based on the average values of the first
         half of the same calendar year. Statements will be made monthly.

<PAGE>
                                     - 27 -

         Net proceeds received for sales to third parties, with freight and
         commissions being deducted (= ex works).

         HK I    for burner discharge = 2,400
                 (0.36 Ti/To + ....)

         HK II   for post-treatment and packaging (actual)

7.    Sachtleben shall be authorized to cancel the purchase of burner discharge
      wholly or partly with a six-month notice if the sales price Sachtleben
      obtains has been below KRONOS' sales prices for burner discharge plus the
      finishing costs incurred by Sachtleben for a period of a quarter of a
      calendar year. In this case, Sachtleben shall bear the fixed operating
      costs of KRONOS that can no longer be reduced or covered due to the loss
      in sale of burner discharge. Sachtleben shall have the right to redeem the
      fixed costs by a one-time payment provided the parties agree on the
      redemption amount.

Art.  13 - Warranty / Liability

1.    Sachtleben warrants that the waste acid used in its waste acid
      reprocessing plant meets the specifications agreed on. KRONOS warrants
      that the waste acid from Leverkusen and the filter salts from Nordenham
      meet the specifications agreed on.

<PAGE>
                                     - 28-

      If the specifications agreed on can be proved to have not been adhered to,
      Sachtleben shall be authorized to refuse to accept and process such
      products inasmuch as it would be impossible within the scope of the valid
      official permits to reprocess the waste acid, decompose the filter salts,
      use the 70 % H2SO4 acid or the fresh acid and dispose of and dump the
      cinders.

      If one of the parties supplies products for processing that do not conform
      to the specifications and if this causes damage or involves additional
      costs or reduced profits in reprocessing the waste acid, decomposition of
      the filter salts or utilisation of the 70 % H2SO4 acid or the fresh acid
      or in disposing of and dumping the cinders, the party concerned shall be
      liable to bear such damage and additional costs or reduced profits.

2.    No other warranties may be claimed with regard to the reprocessing of
      waste acid to 70 % H2SO4 acid, decomposition of filter salts, supply of 70
      % H2SO4 acid and disposal and dumping of cinders.

3.    To the extent that the fresh acid an the burner discharge do not meet the
      stipulated specifications, the parties shall agree on a reasonable price
      reduction. In case it is absolutely impossible for the receiving party to
      use the product received because of non-compliance with the
      specifications, the supplying party undertakes to take back the product
      and to supply a replacement free of charge.

<PAGE>
                                     - 29 -

4.    If for reasons for which Sachtleben is accountable, Sachtleben does not
      meet its obligations to decompose filter salts from Nordenham, Sachtleben,
      according to its choice, shall either take the non-decomposed filter salts
      from KRONOS or refund KRONOS for its expenses for the removal of the
      non-decomposed filter salt quantities.

5.    Further warranty claims and claims exceeding the stipulations of this
      Article shall be excluded.

6.    Contractual damage claims or claims in tort against the other party,
      irrespective of the legal grounds, resulting from the Agreement or being
      in connection with the Agreement, shall be excluded as far as and to the
      extent that this Article does not contain any stipulations to the
      contrary. This is also applicable for legal or other representatives or
      persons employed by either party in the performance of its obligation.
      This does not affect liability of a party for own intent.

      Liability of a party in any case is excluded if said party has acted with
      the diligence it usually employs in its own affairs.

      If notwithstanding, a party is liable for damage claimed by the other
      party, this liability shall be restricted to the direct damages. Damage
      claims resulting from indirect damage, particularly consequential damage,
      property damage or lost profit, shall be excluded.

<PAGE>

                                     - 30 -

7.    If third  parties  claim damage from one of the parties to this  Agreement
      for  damages   resulting  from  or  in  connection  with  this  Agreement,
      especially  for the  dumping  of  cinders  such  damages  shall be  offset
      internally  by the parties to the  Agreement at a ratio of the filter salt
      quantities  from  KRONOS to the  filter  salt  quantities  originating  in
      Sachtleben.  This,  however,  shall not apply if one of the parties to the
      Agreement can be proved to have caused the damage. In this case, the party
      concerned  shall bear the entire  damage and  undertake to  indemnify  the
      other  party.  To the  extent  that at  damage  can be proved to have been
      caused by both parties to the Agreement,  Article 254 of the Federal Civil
      Code shall apply with regard to internal settling between the parties.

      The parties to the Agreement assume that the cinders will be dumped
      together with wastes of third parties. If damages in connection with the
      dumping cannot be proved to have been caused by a party to the Agreement
      or by the third waste producer(s), the parties to the Agreement shall
      share the damage at a ratio of the quantities they dumped to the entire
      quantities dumped, the damage to be borne by the parties to the Agreement
      being settled in compliance with Art. 13, Para. 7,l.

8.    If one of the parties to the Agreement is claimed on by third parties,
      including authorities, because of other measures that result from or are
      in connection with this Agreement (as for instance the disposal of cinders
      in intermediate for final deposition), the stipulations of Paragraph 7
      shall apply accordingly.

<PAGE>
                                     - 31 -

9.    The  obligation  for  offsetting as stipulated in Paragraphs 7 and 8 shall
      apply also after the termination of the Agreement.

Art.  14 - Force Majeure

1.    In case of force majeure, the one party prevented from performing its
      obligations arising from the Agreement shall be obliged to inform the
      other party which contractual obligations cannot be performed and to what
      extent, advising said other party of the reasons that prevent fulfillment
      of the Agreement.

2.    After the end of force majeure, the parties shall agree on reasonable
      measures to be taken to catch up on the contractual obligations affected
      by force majeure. In case this is not possible under acceptable conditions
      and within an acceptable period of time, the contractual obligation
      affected by force majeure shall be dropped either totally or with regard
      to the part that cannot be caught up under acceptable conditions or within
      an acceptable period of time.

3.    In case of force majeure, KRONOS shall store the waste acid generated in
      its production and Sachtleben shall store the 70 % acid generated in its
      own plant each party at its expense. The reprocessing capacity that may
      remain in such cases shall be utilized proportionately for both parties
      (at a ratio of 70 Sachtleben : 30 KRONOS). The waste acid stored at the
      parties' plants shall be reprocessed proportionately in accordance with
      the technical possibilities.

<PAGE>
                                     - 32 -

4.    In case of force majeure, KRONOS shall store filter salt in Nordenham for
      a period of at most 30 days. After the ending of force majeure, Sachtleben
      shall additionally decompose at most the filter salt stored for 30 days,
      within the scope of technical possibilities.

5.    In the event force majeure occurs in connection with the disposal and
      dumping of the cinders (intermediate and final storage), Sachtleben shall
      be authorized to refuse to accept waste acid from Leverkusen and filter
      salt from Nordenham and to discontinue operation of the waste acid
      reprocessing and filter salt decomposition plants for the period of force
      majeure.

6.    Any one party affected by force majeure shall not be held liable for the
      delay or inability caused by this force majeure. Claims of resignation and
      damage claims shall be excluded. Rights resulting from
      ownership/co-ownership allocation shall remain unaffected.

      If an event of force majeure leads to a situation at one of the parties
      that constitutes an unreasonable hardship to the one party, Art. 15 shall
      apply.

7.    Force   majeure  in  the  sense  of  this   stipulation   shall  mean  all
      unforeseeable events or events that are - even if foreseeable - beyond the
      control  of the  parties  and  whose  effects  on the  fulfillment  of the
      Agreement  cannot be prevented by reasonable  efforts made by the parties.
      Such events cover for instance war, war-like situations;  riots;  revolts;
      uproars; outrages;  blockades;  sabotage; strikes; lockouts; fire; floods;

<PAGE>

                                     - 33 -

      natural  disasters of  catastrophic  force;  lightning;  low or high tide;
      total or  partial  failure  of  operating  facilities;  refuse  of  grant,
      abolition, restriction or new creation of official permits or impositions;
      other operating  failures  particularly due to directives or interventions
      of authorities;  inability or delay in the delivery of essential materials
      necessary for the operation of the plants;  refuse of grant,  abolition or
      new  creation of official  permits or  impositions  which,  on the part of
      Sachtleben, lead to an economically unjustifiable disposal of the cinders.

Art.  15 - Hardship Clause

      Upon concluding this Agreement, the parties are aware that they are not in
      a position to fully cover by this Agreement all future situations,
      especially so because of the waste acid reprocessing plant which still has
      to be built.

      If, therefore, a new situation occurs during the term of this Agreement
      and if this Agreement provides no stipulations for handling this situation
      and if this new situation constitutes an unreasonable hardship to one of
      the parties or if this essentially changes the economical balance of this
      Agreement, both parties shall undertake to agree on an adjustment to the
      changed conditions, eliminating the unreasonable hardship and maintaining
      the economical equilibrium.

<PAGE>
                                     - 34 -

Art.  16 - Adjustment of the Agreement

      If an adjustment of the Agreement as provided for in the Agreement cannot
      be reached amicably within six months beginning with the written request
      by one of the parties to the other party, or if the negotiations,
      consultations, arrangements provided for in this Agreement do not lead to
      an agreeable result within this period of time, each of the parties shall
      be authorized to have a court of arbitration decide whether an adjustment
      of the Agreement takes place and on what conditions this can be reached.
      Recourse to arbitration shall be governed by the stipulations of the
      arbitration agreement.

Art.  17 - Secrecy

1.    Each party undertakes to keep secret and to use only within the scope of
      this Agreement any and all experience, knowledge and information obtained
      directly or indirectly from the other party, especially with regard to
      design, construction and operation of the waste acid reprocessing plant
      and with regard to financing and accounting stipulated in this Agreement.

2.    The obligation of secrecy and non-utilization shall exclude any knowledge,
      experience and information that can be proved

      a) to have been commonly known prior to the transfer, that means
         accessible without difficulties and sacrifice to any third party or to
         have become known after the transfer with no fault of the receiving
         party, or

<PAGE>
                                     - 35 -

      b) to have been prior art before the transfer or to have become state of
         the art after the transfer with no fault of the receiving party, or

      c) to have been known to the receiving party at the time of transfer and
         to have been derived neither directly nor indirectly from the
         transmitting party, or

      d) to have been lawfully received by a third party that in this respect is
         not obliged to secrecy towards the transmitting party.

3.    The receiving party shall not be hindered in making the information,
      experience, knowledge received accesible to its employees or other third
      parties to the extent that this is indispensable for the construction and
      operation of the waste acid reprocessing and filter salt decomposition
      plants and for the verification of accounting provided all reasonable
      measures have been taken to prevent employees and other third parties from
      using the information and knowledge obtained either for themselves or for
      others or from passing such information or knowledge to others.

4.    This obligation of secrecy shall be applicable for the period of this
      Agreement and for a period of ten years after termination of the
      Agreement.

5.    Through this Agreement, KRONOS submits to the obligation of secrecy
      stipulated between Sachtleben on the one hand and Bayer AG, Lurgi AG and
      Rosenlew on the other and attached to this Agreement as Exhibit 7.

<PAGE>
                                     - 36 -

Art.  18 - Right of Auditing

      Each party shall have the costs and proceeds relevant to the Agreement
      confirmed by a certified auditor of its choice upon the other party's
      request.

Art.  19 - Transfer of the Agreement / Participation of Third Parties

1.    The transfer - wholly or in part - of the rights and obligations pursuant
      to this Agreement including the stipulated supplies and services, to third
      parties, shall be excluded. This shall not apply if the other one party
      has consented writing to such a transfer. Consent shall be given if one of
      the parties intends to transfer this Agreement wholly or individual
      obligations of it to a company associated within the meaning of the German
      Corporation Law and if such transfer is not expected to result in an
      economic discrimination of the other one party.

2.    Sachtleben shall be entitled, however, to transfer the dumping of the
      cinders to third parties or to take recourse to third parties for this
      dumping. Sachtleben shall inform KRONOS thereof in writing.

3.    In case Sachtleben and/or KRONOS desire to include third parties in all or
      part of the services and supplies to the waste acid reprocessing plant or
      filter salt decomposition, they shall obtain the consent of the other
      party. The conditions of the transfer under which a third party may

<PAGE>
                                     - 37 -

      participate shall likewise be subject to mutual consent. Such consent may
      only be refused if the participation of a third party would mean an
      economic discrimination to the party that is to consent or if waste
      disposal would not be adequately warranted.

Art.  20 - Successor Clause

      In the event one of the parties hereto transfers the plants it requires to
      perform the services and supplies under this Agreement wholly or in part
      to third parties, this party hereto undertakes to transfer the
      corresponding contractual obligations to its successor in title, business
      or ownership provided the other party hereto has given its consent in
      writing to this transfer.

Art.  21 - Taking Effect / Period of the Agreement

1.    This Agreement shall commence on being signed by both parties.

2.    The following services and supplies shall begin and end as follows:

      a) Reprocessing of Leverkusen waste acid including decomposition of the
         filter salts derived from this waste acid and supply of 70 % H2SO4 acid
         and fresh acid: start-up of the waste acid recovery plant (presumably
         on 1 Apr 1989) until 31 Dec 1998.

<PAGE>
                                     - 38 -

      b) Supply of burner discharge presumably on 1 July 1988 till 31 Dec 1998.

      c) Decomposition of Nordenham filter salts presumably on 1 July 1987 till
         31 Dec 1998.

3.    The individual services and supplies may be terminated by a party in
      writing at the end of the respective service or supply period with a three
      years' notice. If no notice of termination is given, the respective
      services and supplies shall continue automatically for further one-year
      periods unless declared terminated by one of the parties with a three
      years' notice.

4.    The stipulations on secrecy and liability shall not be affected by a
      potential termination of individual services or supplies or by a
      termination of the Agreement. This shall also apply to other rights or
      obligations as far as this Agreement assumes their continuation after the
      termination of the Agreement.

Art.  22 - Reservation / Detail Stipulations

1.    Sachtleben's obligation to build the waste acid reprocessing plant and to
      convert the sulphuric acid plant for decomposing filter salts is subject
      to the reservation that the expected subsidies be granted and that the
      permits legally required for the construction and operation of these
      plants be issued. Moreover, the possibility of removing the waste from all
      plants mentioned, especially the cinders that result from the
      decomposition of filter salts, shall be secured by the permits.

<PAGE>
                                     - 39 -

2.    In case the construction or conversion of said plants fails because of
      these reservations, the costs incurred till then under this Agreement
      shall be split up between the parties and refunded.

Art.  23 - Other Cooperation

      Sachtleben and KRONOS declare their basic willingness beyond the present
      project to cooperate also on other problems regarding environmental
      protection requirements unless such cooperation is prevented by legal or
      contractual obligations.

Art.  24 - Termination of the Provisional Agreement

      The parties hereto agree that the provisional agreement dated 18 July 1986
      shall become moot upon the signing of this Agreement.

Art.  25 - Arbitration Clause

      Disputes arising from or in connection with this Agreement, which cannot
      be settled amicably between the two parties, shall be settled by a court
      of arbitration, ousting general jurisdiction. Details shall be settled in
      the arbitration agreement concluded by the parties on 18 July 1986. The
      parties agree that this arbitration agreement shall have exclusive and
      unlimited validity also for this Agreement including all post-contractual
      rights and obligations.

<PAGE>
                                     - 40 -

Art.  26 - Clause on Partial Invalidity

      In the event individual stipulations of the Agreement are or become wholly
      or partly ineffective, this shall not affect the validity of the remaining
      part of the Agreement. The parties undertake to replace the ineffective
      stipulation with an effective one that comes as close as possible to the
      economic objective aimed at by the ineffective stipulation.

Art.  27 - Written-Form Clause

      Alterations of or supplements to this Agreement, including the
      Written-Form Clause, must be made in writing to become effective.

Duisburg-Homberg, 30 December 1986          Leverkusen, 30 December 1986
Sachtleben Chemie GmbH                      KRONOS TITAN-GMBH

/s/ Dr. Kleist     Dr. Herrmann            /s/ Dr. S. Hartmann     Dr. J. Hoene
-----------------------------------        -------------------------------------
    Dr. Kleist     Dr. Herrmann                Dr. S. Hartmann     Dr. J. HoeneEXHIBIT 10.2

                                                          23 April 1996

                             Supplementary Agreement
                      to the Agreement of 30 December 1986

between

Sachtleben Chemie GmbH, Dr.-Rudolf-Sachtleben-Strasse 4, 47198 Duisburg

                                   - hereinafter referred to as "Sachtleben" -

and

KRONOS TITAN-GMBH, Peschstrasse 5, 51373 Leverkusen

                                   - hereinafter referred to as "KRONOS" -

WHEREAS,

By date of 30 December 1986 the parties concluded an Agreement on the
reprocessing of the spent acid generated in the production of titanium dioxide
in the Leverkusen and Homberg plants, on the decomposition of the filter salts
derived from this spent acid and of further filter salts supplied from
Nordenham, on the supply of fresh acid generated from the filter salts and the
supply of burner discharge.

After discontinuation of the roasting of Meggen pyrites in spring 1995 the
sulphuric acid plant at Homberg previously partly converted for the
decomposition of filter salts finally will no longer be operated mainly for
producing sulphuric acid, but for decomposing filter salts.

The parties agree that the economic balance of this Agreement is essentially
affected by the new situation of the sulphuric acid plant.

THEREFORE, by this Supplementary Agreement the parties intend pursuant to the
Hardship Clause (Section 15) to adjust the Agreement of 30 December 1986 to the
changed conditions by eliminating the unreasonable hardship for Sachtleben and
by maintaining the economic equilibrium.

<PAGE>

                                      - 2 -

1.      Definitions
        The following provisions replace the stipulations of Section 1 (4) fresh
        acid and explain Section 1 (13) filter salt quantities of the Agreement
        of 30 December 1986. The new definitions are:

1.1     Fresh Acid
        Fresh acid shall mean the sulphuric acid produced in the Homberg
        sulphuric acid plant. The fresh acid derived from the decomposition of
        filter salts is divided into equivalent acid and concurrent acid.

1.1.1.  Equivalent Acid
        Equivalent acid shall mean the fresh acid produced from filter salts and
        from the adhering spent acid reconcentrated to approximately 70 percent,
        which fresh acid is adjusted for KRONOS to about 96 percent sulphuric
        acid.

1.1.2.  Concurrent acid
        Concurrent acid shall mean the fresh acid additionally produced in the
        Homberg sulphuric acid plant during the decomposition of filter salts,
        which acid results from the use of pyrite, sulphur or other sulphurous
        material. The concurrent acid is likewise adjusted for KRONOS to about
        96 percent sulphuric acid.

1.2.    Filter Salt Quantities
        At the beginning of each subsequent year, the filter salt quantities
        from Leverkusen and Homberg shall be determined for the final account of
        the preceding year as follows: In a first step the theoretical filter
        salt quantities shall be calculated from the analyses of the spent acid
        supplied by the two plants. The same applies to spent acid quantities
        supplied from third parties for reprocessing. In case the theoretical
        total quantity thus calculated differs from the total actual quantity
        weighed, the differing quantity shall be apportioned to the various
        supplier sources in proportion to the theoretical quantities obtained.

        The factor obtained from the corrected final account of the preceding
        year for the quantity of filter salt in kilogram as is per ton of spent
        acid shall be used for the calculation of the current year. The quantity
        of filter salts from Nordenham shall be calculated - as up to now - from
        the incoming quantities weighed.

<PAGE>
                                      - 3 -

2.      Decomposition of Filter Salts/Disposal of Cinders/Supply of Fresh Acid
        Art. 2 of this Supplementary Agreement shall replace Section 6
        (completely) as well as Paragraphs 1., 2., 4., 5., and 6. of Section 11
        of the Agreement of 30 December 1986.

2.1.1.  Sachtleben shall decompose - together with other filter salts - the
        filter salts supplied by KRONOS from Nordenham as well as the filter
        salts generated in reprocessing the spent acid from Leverkusen, by use
        of pyrite and/or sulphur as well as coal and/or other material.

2.1.2.  The Homberg filter salt decomposition plant/sulphuric acid plant has a
        capacity to decompose 244,000 t filter salt per year.

        KRONOS shall have the right to have up to 110,000 tons of filter salt
        (as obtained in reprocessing of the Leverkusen spent acid and/or as
        supplied from Nordenham) decomposed by Sachtleben in the filter salt
        decomposition plant. These 110,000 tons of filter salt correspond to 45
        percent of the capacity, the other 55 percent shall be used by
        Sachtleben for decomposing filter salts corresponding up to 134,000 t
        filter salt per calendar year.

        In case one of the two parties declares an essentially higher or lower
        demand of decomposition capacity than it is entitled to for an extended
        period of time, Sachtleben shall examine an adaptation of the plant
        capacity if a capacity exchange between both parties is not possible. In
        case of a capacity modification or exchange of capacity, the capacity
        allocation - at present 55 Sachtleben : 45 KRONOS - shall be newly
        determined.

        In case of Force Majeure the possibly remaining capacity of the filter
        salt decomposition plant shall be used proportionately (at a ratio of 55
        Sachtleben : 45 KRONOS) and the filter salts stored at each party's
        plant shall be processed subsequently according to the ratio taking into
        account the technical feasibility.

2.2.1.  Sachtleben shall dispose of the cinders resulting from the decomposition
        of KRONOS filter salts as far as - at reasonable conditions - possible.
        The parties agree that KRONOS shall obtain a co-ownership in the total
        cinders generated according to Art. 2.1.1. of this Supplementary
        Agreement, viz. proportionately to the filter salt quantities decomposed
        for KRONOS related to the total filter salt quantities decomposed. The
        rights and obligations resulting from the ownership/co-ownership shall
        be independent of the obligations assumed by Sachtleben under this
        Agreement. Also beyond the

<PAGE>
                                      - 4 -

        termination of the Agreement, KRONOS shall proportionately to its
        co-ownership share liabilities and risks for the total cinders generated
        till the termination of the Agreement.

2.2.2.  The current costs required for the disposal of the cinders including the
        operating costs for the intermediate storage pile IV as well as
        potential treatment cost shall be allowed for according to Art. 3. of
        this Supplementary Agreement. Sachtleben assumes that all cinders
        generated can further be disposed of as since May 1993.

        Costs for further intermediate storage or final depositing will be
        shared between KRONOS and Sachtleben at the ratio of their agreed
        ownerships in the cinders. KRONOS shall pay its share in the costs
        immediately after they have been incurred and calculated as far as these
        costs were not yet settled pursuant to Art. 3. of this Supplementary
        Agreement.

        KRONOS's cost sharing for cinder disposal shall not be affected by a
        potential termination of the Agreement.

        Sachtleben shall inform KRONOS about essential developments regarding
        dumping of the cinders.

2.3.1.  KRONOS shall be allocated a certain quantity of fresh acid in proportion
        to the filter salt supplied. The quantity of fresh acid to be
        apportioned to KRONOS shall be calculated by breaking down the entire
        sulphuric acid quantity produced at the Homberg sulphuric acid plant
        (calculated as 100 percent sulphuric acid) proportionately to the filter
        salt quantities supplied by KRONOS related to the total quantity.

2.3.2.  Sachtleben shall supply KRONOS with equivalent acid. KRONOS shall
        continuously take for each ton of filter salt from Nordenham or
        Leverkusen spent acid (cf. 1.2.) 0.60 tons fresh acid 100 percent,
        delivered as 96 percent fresh acid. The acids shall be taken by KRONOS
        as up to now.

2.3.3.  The amount of concurrent acid to be apportioned to KRONOS shall be
        calculated from the difference between the total quantity of fresh acid
        to be apportioned pursuant to Art. 2.3.1. and the quantity of equivalent
        acid to be apportioned pursuant to Art. 2.3.2. of this Supplementary
        Agreement.

        Up to 31 December 1996, Sachtleben shall continue to sell the concurrent
        acid attributable to KRONOS, delivered as 96 percent fresh acid, via the
        previous distribution channel. Following 31 December 1996 Sachtleben
        shall provide

<PAGE>
                                      - 5 -

        KRONOS with the total concurrent acid to be apportioned to KRONOS and
        KRONOS shall continuously take this acid. The equivalent acid and
        concurrent acid quantities shall be calculated separately for the last
        time in the final account of the year 1996.

2.3.4.  The price for the fresh acid taken by KRONOS, i.e. equivalent acid and
        concurrent acid, is determined to be 0.00 DM.

        Sachtleben shall pay KRONOS a compensation for the concurrent acid still
        sold via the previous distribution channel corresponding to the
        quarterly determined average sales price of Sachtleben ex works Homberg
        (after sales commission) for 96 percent fresh acid from the sales to
        third parties.

2.3.5.  Following 31 December 1996 KRONOS shall market the entire fresh acid it
        is entitled to via the MG Chemiehandel GmbH as far as the fresh acid
        shall not be taken for its own demand. The pertaining agreements shall
        be negotiated separately between MG Chemiehandel and KRONOS.

        Should, during the period of the Agreement, a new situation arise which
        makes adherence to the present provisions unreasonable for KRONOS,
        Sachtleben and KRONOS shall adjust Art. 2.3.5. by maintaining the
        economic equilibrium.

3.      Costs for the Decomposition of KRONOS Filter Salts
        Art. 3. of this Supplementary Agreement shall replace Section 9
        (completely) as well as Paragraph 3. of Section 11 of the Agreement of
        30 December 1986.

        The costs of decomposing the filter salts shall be calculated on the
        basis of the cost calculation system installed at Sachtleben (at present
        SAP differential planning cost) for which company-uniform accounting
        principles are applied. Difference is made between variable and fixed
        costs.

3.1.    Variable Costs
        The variable actual costs which particularly include the costs for
        pyrite, sulphur, and coal as well as the variable parts of the energy
        costs and the steam credit shall be charged to Sachtleben and KRONOS
        proportionately to the filter salts used.

3.2.    Fixed Costs

        The fixed costs shall be  apportioned  in relation to the capacity claim
        pursuant to Art. 2.1.2. of this Supplementary Agreement.

<PAGE>
                                      - 6 -

3.3     Invoicing
        The  invoice  to  be   submitted  by   Sachtleben   to  KRONOS  for  the
        decomposition  of filter salts  includes  the sum of the variable  costs
        pursuant to Art. 3.1. and the fixed costs pursuant to Art. 3.2. plus the
        current value added tax.

3.4.    Pursuant to Section 18 of the Agreement of 30 December 1986 KRONOS may
        check the costs invoiced by Sachtleben to KRONOS pursuant to Art. 3.3.

4.      Lump-Sum Remuneration
        Art. 4. of this Supplementary Agreement shall replace Section 10
        (completely) of the Agreement of 30 December 1986.

        In addition to the share in capital charges and operating costs, KRONOS
        shall pay Sachtleben a monthly lump sum effective January 1996 for the
        remaining period of this Supplementary Agreement for the reprocessing of
        the Leverkusen spent acid and the decomposition of the filter salts
        generated therefrom as well as for the decomposition of the Nordenham
        filter salts.

        The lump-sum payment shall be calculated by using extra charges
        expressed in percent of the costs charged by Sachtleben to KRONOS for
        the reprocessing of spent acid and the decomposition of filter salts.
        The extra charges shall amount to 3.5 percent for the reprocessing of
        spent acid and to 7 percent for the decomposition of filter salts.

5.      Capital Expenditures for the Sulphuric Acid Plant
        Decisions on capital expenditures for the Homberg sulphuric acid plant
        shall be made solely by Sachtleben and be financed by Sachtleben on its
        own decision without any obligation of KRONOS to share the expenditures.
        These investments shall be considered in the cost accounting system via
        the capital service and thus in the costs to be proportionately charged
        to KRONOS by Sachtleben pursuant to the stipulations in Art. 3. of this
        Supplementary Agreement.

<PAGE>

                                      - 7 -

6.      Taking Effect/Period of Agreement

6.1.    This Agreement shall become effective on 1 September 1995 and shall be
        valid exclusively for the supplies and services effected from this date
        on.

6.2.    Regarding decomposition of the Nordenham filter salts, the period of
        notice pursuant to Section 21 Paragraph 3 Sentence 1 of the Agreement of
        30 December 1986 for the termination of supplies and/or services shall
        be extended from 3 to 4 years.

        Regarding reprocessing of the spent acid from Leverkusen and of the
        filter salts derived from this spent acid: Should KRONOS shut down the
        sulfate route production of titanium dioxide in the Leverkusen plant,
        the period of notice pursuant to Section 21 Paragraph 3 Sentence 1 for
        the termination of supplies and/or services shall be reduced from 3
        years to 6 months. In this shutdown case, KRONOS will also be free of
        the obligation to pay the proportionate fixed costs as of the end of the
        relevant accounting period. In this case, Sachtleben and KRONOS
        conjointly will newly determine the sharing of the fixed costs for
        decomposition of filter salts from Homberg and Nordenham by maintaining
        the economic equilibrium. The notice pursuant to this paragraph can
        first be given with effect for 31 December 1998.

6.3.    The Agreement of 30 December 1986 shall continue to be effective
        unchanged unless modified by express stipulation of this Supplementary
        Agreement.

Duisburg-Homberg, April 30, 1996        Leverkusen, May 3, 1996

Sachtleben Chemie GmbH                  KRONOS TITAN-GMBH

/s/ Dr. Griebler      Mr. Trippe        /s/ Dr. E. Gartner          Dr. J. Hoene
    --------------------------------    ------------------------------------
    Dr. Griebler      Mr. Trippe            Dr. E. Gartner          Dr. J. Hoene

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