EXHIBIT 10.11

                         AMCOL International Corporation
                      Fourth Amendment to Credit Agreement



Harris Trust and Savings Bank
Chicago, Illinois

The First National Bank of
Chicago, Illinois

LaSalle National Bank
Chicago, Illinois

The Northern Trust Company
Chicago, Illinois

Bank of America National
Trust and Savings Association
Chicago, Illinois


Ladies and Gentlemen:

     Reference is made to that certain Credit  Agreement  dated as of October 4,
1994  as  heretofore   amended  (the  "Credit   Agreement")  by  and  among  the
undersigned, AMCOL International Corporation (formerly known as American Colloid
Company), a Delaware corporation (the "Company"),  Harris Trust and Savings Bank
in its capacity as Agent (the "Agent") and you (collectively,  the "Banks"). The
Company  applies to the Banks for their  agreement  to  increase  the  aggregate
amount of the Revolving Credit to  $125,000,000,  extend the Termination Date of
the Revolving Credit, add Bank of America National Trust and Savings Association
as a Bank  under the  Credit  Agreement  and amend  certain  terms of the Credit
Agreement  in the  manner  and on the terms  and  conditions  set forth  herein.
Capitalized terms used in this Amendment and not otherwise  specifically defined
have the meaning given such terms in the Credit Agreement.

Section 1. Addition of New Bank.

     Upon satisfaction of all of the conditions precedent set forth in Section 3
of this Amendment:

     Section 1.1. Bank of America  National Trust and Savings  Association  (the
"New Bank")  shall assume the role of a Bank under the Credit  Agreement  with a
Commitment in the
<PAGE>
principal amount of $20,000,000 (the "New Commitment").  The New Bank shall have
all the rights and, from and after the date this  Amendment  becomes  effective,
obligations  currently held by all the Banks. The parties hereto consent to such
addition  of the New Bank and the New  Commitment  under the  Credit  Agreement.
Notwithstanding  anything contained herein to the contrary,  the increase of the
Commitments  contemplated  by the  addition  of the New Bank  shall  not  become
effective  until  the  satisfaction  of the  conditions  precedent  set forth in
Section 3 hereof. Accordingly, all references in the Credit Agreement, Notes and
Guaranty Agreements (collectively, the "Loan Documents") to the terms "Bank" and
"Banks" shall be deemed to include, and be a reference to, the New Bank.

     Section 1.2. All references in the Credit  Agreement and the Loan Documents
to the Notes or any of them shall be deemed to include,  and be a reference  to,
the Revolving Credit Note issued pursuant hereto by the Company to the New Bank.

     Section  1.3.  The New Bank shall be deemed a Bank  signatory to the Credit
Agreement and the following  address and Commitment shall be deemed to appear on
the Banks'  signature  page in the Credit  Agreement  as so amended  for the New
Bank:

                            231 South LaSalle Street
                             Chicago, Illinois 60697
                             Attention: Daniel Lange
                          Commitment: $20,000,000 (16%)
                             Telephone: 312-828-2756
                            Telecopier: 312-828-6647

Section 2.           Amendments To Credit Agreement.

     Upon satisfaction of all of the conditions precedent specified in Section 3
of this Amendment, the Credit Agreement shall be amended as follows:

     Section 2.1. The definition of "Termination Date" appearing in Section 4 of
the Credit  Agreement  shall be amended by deleting the date  "October 31, 2000"
appearing therein and by substituting therefor the date "October 31, 2003".

     Section 2.2.  Section 4 of the Credit Agreement shall be further amended by
adding the following new definition thereto:

          "Year 2000 Problem" means any significant risk that computer hardware,
     software,  or equipment  containing  embedded  microchips  essential to the
     business or operations of the Company or any of its Subsidiaries  will not,
     in the case of dates or time  periods  occurring  after  December 31, 1999,
     function at least as  efficiently  and  reliably as in the case of times or
     time periods  occurring  before  January 1, 2000,  including  the making of
     accurate leap year calculations.
<PAGE>

     Section 2.3.  Section 6 of the Credit  Agreement shall be amended by adding
the following new Section 6.3 at the end thereof:

          "Section  6.3. The Company is  conducting a  comprehensive  review and
     assessment of the computer applications of the Company and its Subsidiaries
     and  is  making  inquiry  of  their  material  suppliers,  service  vendors
     (including data  processors)  and customers,  with respect to any defect in
     computer software,  data bases, hardware,  controls and peripherals related
     to the occurrence of the year 2000 or the use at any time of any date which
     is before, on and after December 31, 1999, in connection  therewith.  Based
     on the foregoing review,  assessment and inquiry, the Company believes that
     no such defect  could  reasonably  be  expected to have a material  adverse
     effect on the  business  or  financial  affairs of the  Company  (or of the
     Company and its Subsidiaries taken on a consolidated basis)."

     Section 2.4.  Subsections (e), (f), (g), (h) and (i) of Section 7.15 of the
Credit  Agreement shall be deleted and the following  subsections  (e), (f), (g)
and (h) shall be inserted in their stead:

          "(e) investments in, and loans and advances to, Domestic Subsidiaries;

          (f) investments in, and loans and advances to, Restricted Subsidiaries
     (other than Domestic  Subsidiaries)  provided such  investments,  loans and
     advances  at  any  one  time  outstanding  do  not  exceed  the  sum of (i)
     $100,000,000 plus (ii) the amount (if any) by which (A) $50,000,000 exceeds
     (B) the aggregate  amount  outstanding on  investments,  loans and advances
     permitted solely by virtue of subsection (h) of this Section;

          (g)  acquisitions,  provided  that (i) no  Default or Event of Default
     exists or would exist after  giving  effect to such  acquisition,  (ii) the
     board of directors or other governing body of such Person whose property or
     Voting  Stock  is  being  so  acquired  has  approved  the  terms  of  such
     acquisition  and (iii) prior to each  acquisition  requiring  consideration
     from the Company and its  Subsidiaries in excess of $10,000,000,  (x) there
     is  delivered  to the Banks a  certificate,  signed by the chief  financial
     officer of the  Company,  demonstrating  that,  taking  into  account  such
     acquisition and its effects, the Company will remain in compliance with the
     covenants  set forth in Sections  7.6, 7.7 and 7.8 hereof as of the date of
     such  acquisition  and, based on projections  believed by the Company to be
     reasonable, at all times during the twelve month period following such date
     and  certifying  that no  Default or Event of Default  has  occurred  or is
     continuing  hereunder as of the date of and immediately after giving effect
     to such acquisition and (y) such certificate is true and correct; and
<PAGE>

          (h) any other investments,  loans and advances not otherwise permitted
     by this Section in an aggregate amount not to exceed $50,000,000."

     Section 2.5.  Section 7 of the Credit  Agreement shall be amended by adding
the following new Section 7.18 at the end thereof:

          "Section  7.18.  Year 2000  Assessment.  The  Company  shall  take all
     actions  necessary  and  commit  adequate  resources  to  assure  that  its
     computer-based  and other systems (and those of all  Subsidiaries) are able
     to effectively process dates,  including dates before, on and after January
     1, 2000,  without  experiencing  any Year 2000  Problem  that could cause a
     material adverse effect on the business or financial affairs of the Company
     (or of the Company and its Subsidiaries taken on a consolidated  basis). At
     the request of the Banks,  the Company  will provide the Banks with written
     assurances and substantiations  (including, but not limited to, the results
     of internal or external  audit reports  prepared in the ordinary  course of
     business)  reasonably  acceptable to the Banks as to the  capability of the
     Company  and its  Subsidiaries  to  conduct  its and their  businesses  and
     operations  before,  on and after January 1, 2000,  without  experiencing a
     Year 2000  Problem  causing a material  adverse  effect on the  business or
     financial  affairs of the Company  (or of the Company and its  Subsidiaries
     taken on a consolidated basis)."

     Section  2.6.  The  portion  of the  Banks'  signature  pages to the Credit
Agreement  under the column headed "Amount of  Commitments"  shall be amended in
its entirety and as so amended shall read as follows:

               Amount and
              Percentage of
              Commitments:                                      Bank:

              $35,000,000                     Harris Trust and Savings Bank
                 (28%)

              $25,000,000                     The First National Bank of Chicago
                 (20%)

              $15,000,000                     LaSalle National Bank
                 (12%)

              $30,000,000                     The Northern Trust Company
                 (24%)
<PAGE>

Section 3.           Conditions Precedent.

     The  effectiveness  of this Amendment is subject to the satisfaction of all
of the following conditions precedent:

     Section 3.1. The Company,  the Agent and the Banks (including the New Bank)
shall  have  executed  this  Amendment   (such   execution  may  be  in  several
counterparts   and  the   several   parties   hereto  may  execute  on  separate
counterparts).

     Section  3.2.  The Agent shall have  received  (i) for  delivery to Bank of
America  National Trust and Savings  Association  and The Northern Trust Company
(each an "Amending  Bank") new  Revolving  Credit Notes  payable to the order of
each Amending Bank in the face principal  amount of its Commitment  after giving
effect  to this  Amendment,  such  new  Revolving  Credit  Notes  to  constitute
"Revolving  Credit  Notes" for all  purposes  of the Credit  Agreement  upon the
Agent's  receipt of the same for each  Amending  Bank and (ii) for return to the
Company the existing  Revolving Credit Notes heretofore  issued to each Amending
Bank.

     Section 3.3. The Agent shall have received an executed  Guarantors' Consent
in the form attached hereto.

     Section 3.4. The Banks shall have received copies (executed or certified as
may be appropriate)  of all legal  documents or proceedings  taken in connection
with the execution and delivery of this Amendment and the other  instruments and
documents contemplated hereby and an opinion of counsel to the Company in a form
satisfactory to the Banks.

     Section  3.5.  Each of the  representations  and  warranties  set  forth in
Section 5 of the Credit  Agreement  shall be true and correct  (except  that the
representations contained in Section 5.4 of the Credit Agreement shall be deemed
to refer to the most recent financial statements of the Company delivered to the
Banks  pursuant to Section 7.14 of the Credit  Agreement).  The Company  further
represents  and  warrants  that  the  Guarantors  listed  on  Exhibit  A  hereto
constitute all of the Company's  Domestic  Subsidiaries  existing as of the date
hereof

     Section 3.6. The Company shall be in full  compliance with all of the terms
and conditions of the Credit  Agreement and no Event of Default or Default shall
have occurred and be  continuing  thereunder or shall result after giving effect
to this Amendment.

Section 4.           Reallocation of Eurocurrency Loans.

     If upon this Amendment  becoming effective there are any Loans outstanding,
but in that event  anything  contained  in the Credit  Agreement to the contrary
notwithstanding, substantially concurrent with this Amendment becoming effective
there  shall be such  nonratable  Borrowings  and  repayments  under the  Credit
Agreement,  as amended hereby,  so that, after giving effect thereto,  each Bank
holds its ratable  share (with  ratably for such  purposes to be  determined  in
accordance with the Banks'  respective  Commitments  after giving effect to this
Amendment) of the total of the Loans then outstanding;  provided,  however, that
if there are any Eurocurrency
<PAGE>

Loans outstanding on such date, then in that event and to that extent nonratable
Loans and repayments shall not, unless the Company  otherwise  elects,  it being
understood  that such an  election  will be subject to payment of any amount due
the Banks  (under  Section 2.5 hereof) be made on such date but rather  shall be
made on the last day of each interest  period  applicable  to each  Eurocurrency
Loan, all to the end that all Loans outstanding under the Credit Agreement shall
be made ratably from each Bank according to its Commitment in effect after given
effect  to  this  Amendment  at the  earliest  date on  which  the  same  can be
accomplished  without requiring that a Eurocurrency Loan be paid on a date other
than the last day of the  interest  period  applicable  thereto.  If during such
period, additional Borrowings are requested, the Company acknowledges and agrees
that it shall only request Borrowings in amounts which will permit the Loans for
each  such  Borrowing  to be  made  ratably  from  each  Bank  according  to its
Commitment  in effect after giving  effect to this  Amendment and which will not
cause such Loans to exceed any Bank's Commitment.  The parties hereto understand
and acknowledge  and agree that the percentage of the New Bank's  Commitments in
use in the  form of  Eurocurrency  Loans  may,  upon the  effectiveness  of this
Amendment, be less than the percentage of the other Banks' Commitments in use in
the form of Eurocurrency  Loans.  The Commitment Fee accruing during this period
shall be allocated  among the Banks in accordance with their  Commitments  after
giving effect to this Amendment.

Section 5.           Miscellaneous.

     Section 5.1.  Except as  specifically  amended herein the Credit  Agreement
shall  continue in full force and effect.  Reference to this specific  Amendment
need  not be  made  in any  note,  document,  letter,  certificate,  the  Credit
Agreement  itself,  the Revolving  Credit Notes,  the Guaranty  Agreement or any
communication  issued or made pursuant to or with respect thereto, any reference
to the Credit  Agreement in any of such being  sufficient to refer to the Credit
Agreement as amended hereby.

     Section  5.2.  The  Company  shall  pay all  fees and  expenses  (including
attorneys'  fees)  incurred  by Harris  Trust and  Savings  Bank and its counsel
incurred in connection  with the drafting and  preparation,  and  supervision of
legal matters in connection with this Amendment.

     Section 5.3. This Amendment may be executed in any number of  counterparts,
and by the  different  parties on  different  counterparts,  all of which  taken
together shall constitute one and the same Agreement.  Any of the parties hereto
may execute  this  Amendment  by signing any such  counterpart  and each of such
counterparts shall for all purposes be deemed to be an original.  This Amendment
shall be governed by the internal laws of the State of Illinois.
<PAGE>
Dated as of this 15th day of December, 1998.

                            AMCOL International Corporation (formerly known as
                                                      American Colloid Company)


                                                    By   /s/ Paul G. Shelton
                                                      Its  Senior Vice President



Accepted and agreed to as of the day and year last above written.

                                              Harris Trust and Savings Bank,
                                                individually and as Agent

                                              By   /s/ Ray Whitacre
                                                Its Vice President


                                              The First National Bank of Chicago


                                              By   /s/ Barry Litwin
                                                Its Senior Vice President


                                              LaSalle National Bank


                                              By   /s/ Richard Bott
                                                Its Senior Vice President


                                              The Northern Trust Company


                                              By  /s/ Daniel R. Hintzen
                                                Its Vice President


                                               Bank of America National Trust
                                                and Savings Association


                                               By  /s/  Daniel Lange
                                                 Its Vice President
<PAGE>

                               Guarantors' Consent

     The  undersigned  are  party to that  certain  Joint and  Several  Guaranty
Agreement  dated  as  of  October  4,  1994  (as  supplemented,   the  "Guaranty
Agreement"),  and hereby consent to the amendment of the Credit Agreement as set
forth  above  and  confirm  that  such   Guaranty   Agreement  and  all  of  the
undersigneds'  obligations  thereunder remain in full force and effect.  Without
limiting the generality of the foregoing,  the undersigned acknowledge and agree
that all references to the "Credit Agreement" in the Guaranty Agreement shall be
deemed  references to the Credit Agreement as amended by the Fourth Amendment to
Credit  Agreement  and further  agree that any reference in such Guaranty to the
Company's  former  name,  "American  Colloid  Company"  shall be  amended  to be
references  to the  Company's new name "AMCOL  International  Corporation".  The
undersigned  further  agree that the consent of the  undersigned  to any further
amendments  of the Credit  Agreement  shall not be  required as a result of this
consent  having been  obtained,  except to the extent,  if any,  required by the
Guaranty Agreement referred to above.

      Dated as of December __, 1998.

                                         Ameri-Co Carriers, Inc.


                                         By  /s/ Paul G. Shelton
                                           Its President

                                         Nationwide Freight Service, Inc.


                                         By  /s/ Paul G. Shelton
                                            Its President

                                         Chemdal Corporation


                                         By  /s/ Paul G. Shelton
                                            Its Treasurer

                                         Superior Absorbents, Inc.


                                          By  /s/ Paul G. Shelton
                                             Its Treasurer
<PAGE>

                                           Montana Minerals Development Company


                                           By  /s/ Paul G. Shelton
                                              Its Treasurer

                                           Chemdal International Corporation

                                           By  /s/ Paul G. Shelton
                                              Its Treasurer

                                           Regeneration Technologies, Inc.


                                           By  /s/ Paul G. Shelton
                                              Its Treasurer

                                          Colloid Environmental Technologies
                                            Company


                                           By  /s/ Paul G. Shelton
                                              Its Treasurer

                                           American Colloid Company (f.k.a. AES
                                             Acquisition, Inc.and American
                                             Colloid Mineral Company)


                                           By  /s/ Paul G. Shelton
                                              Its Treasurer

                                           Volclay International Corporation


                                           By  /s/ Paul G. Shelton
                                              Its Treasurer

                                           Nanocor, Inc.


                                           By  /s/ Paul G. Shelton
                                              Its Treasurer

<PAGE>

                                    Exhibit A

                              Domestic Subsidiaries


                 Name                             Jurisdiction of Incorporation

Ameri-Co Carriers, Inc.                                     Nebraska

Nationwide Freight Service, Inc.                            Nebraska

Chemdal Corporation                                         Delaware

Superior Absorbents, Inc.                                   Delaware

Montana Minerals Development Company                        Montana

Chemdal International Corporation                           Delaware

Regeneration Technologies, Inc. (f.k.a. Amcol               Delaware
   International Corp.)

Colloid Environmental Technologies Company                  Delaware

American Colloid Company (f.k.a. AES                        Delaware
   Acquisition, Inc. and American Colloid Mineral Company)

Nanocor, Inc.                                               Delaware

Volclay International Corporation                           Delaware

<PAGE>