Exhibit 10.15
                         THE RANDERS GROUP INCORPORATED

              RESTATED STOCK HOLDING ASSISTANCE PLAN


SECTION 1.   Purpose.

      The purpose of this Plan is to benefit The Randers Group Incorporated (the
"Company")  and its  stockholders  by  encouraging  Key Employees to acquire and
maintain  share  ownership  in  the  Company,   by  increasing  such  employees'
proprietary  interest in promoting the growth and performance of the Company and
its  subsidiaries and by providing for the  implementation  of the Stock Holding
Policy.

SECTION 2. Definitions.

      The following  terms,  when used in the Plan,  shall have the meanings set
forth below:

      Committee:   The Human Resources Committee of the Board of
Directors of the Company as appointed from time to time.

      Common Stock:   The common stock of the Company and any
successor thereto.

      Company:   The Randers Group Incorporated, a Delaware
corporation.

      Stock Holding Policy:   The Stock Holding Policy of the
Company, as adopted by the Committee and as in effect from time
to time.

      Key  Employee:  Any  employee of the  Company or any of its  subsidiaries,
including  any  officer  or  member  of the  Board of  Directors  who is also an
employee,  as  designated  by the  Committee,  and who,  in the  judgment of the
Committee,  will be in a position to contribute  significantly to the attainment
of the Company's strategic goals and long-term growth and prosperity.

      Loans:   Loans extended to Key Employees by the Company
pursuant to this Plan.

      Plan:   The Randers Group Incorporated Stock Holding
Assistance Plan, as amended from time to time.

SECTION 3. Administration.

      The  Plan and the  Stock  Holding  Policy  shall  be  administered  by the
Committee,  which  shall  have  authority  to  interpret  the Plan and the Stock
Holding Policy and, subject to their provisions, to prescribe, amend and rescind
any rules and  regulations  and to make all other  determinations  necessary  or
desirable for the administration  thereof.  The Committee's  interpretations and
decisions  with regard to the Plan and the Stock  Holding  Policy and such rules
and regulations as may be established  thereunder shall be final and conclusive.
The  Committee  may correct any defect or supply any omission or  reconcile  any
inconsistency  in the Plan or the Stock  Holding  Policy,  or in any Loan in the
manner and to the extent the Committee  deems desirable to carry it into effect.
No member  of the  Committee  shall be liable  for any  action  or  omission  in
connection with the Plan or the Stock Holding Policy that is made in good faith.

SECTION 4. Loans and Loan Limits.

      The Committee has determined that the provision of Loans from time to time
to Key  Employees in such amounts as to cause such Key  Employees to comply with
the Stock  Holding  Policy  is, in the  judgment  of the  Committee,  reasonably
expected to benefit the Company and  authorizes the Company to extend Loans from
time to time to Key  Employees  in such  amounts as may be requested by such Key
Employees in order to comply with the Stock  Holding  Policy.  Such Loans may be
used  solely for the  purpose of  acquiring  Common  Stock  (other than upon the
exercise of stock options or under employee stock purchase plans) in open market
transactions or from the Company.

      Each Loan shall be full recourse and evidenced by a  non-interest  bearing
promissory  note  substantially  in the form  attached  hereto as Exhibit A (the
"Note") and maturing in accordance with the provisions of Section 6 hereof,  and
containing such other terms and conditions,  which are not inconsistent with the
provisions of the Plan and the Stock  Holding  Policy,  as the  Committee  shall
determine in its sole and absolute discretion.

SECTION 5. Federal Income Tax Treatment of Loans.

      For federal income tax purposes, interest on Loans shall be imputed on any
interest  free Loan extended  under the Plan. A Key Employee  shall be deemed to
have paid the imputed interest to the Company and the Company shall be deemed to
have  paid  said  imputed  interest  back  to the  Key  Employee  as  additional
compensation.  The deemed  interest  payment  shall be taxable to the Company as
income,  and may be deductible to the Key Employee to the extent allowable under
the rules relating to investment  interest.  The deemed compensation  payment to
the Key Employee shall be taxable to the employee and deductible to the Company,
but shall also be subject to employment taxes such as FICA and FUTA.

SECTION 6. Maturity of Loans.

      Each Loan to a Key Employee  hereunder  shall be due and payable on demand
by the Company.  If no such demand is made,  then each Loan shall mature and the
principal  thereof shall become due and payable on the fifth  anniversary of the
date of the Loan,  provided  that the  Committee  may, in its sole and  absolute
discretion,  authorize  such  other  maturity  and  repayment  schedule  as  the
Committee may determine. Each Loan shall also become immediately due and payable
in full,  without demand,  upon the occurrence of any of the events set forth in
the Note; provided that the Committee may, in its sole and absolute  discretion,
authorize an  extension of the time for  repayment of a Loan upon such terms and
conditions as the Committee may determine.

SECTION 7. Amendment and Termination of the Plan.

      The  Committee  may from time to time alter or amend the Plan or the Stock
Holding Policy in any respect, or terminate the Plan or the Stock Holding Policy
at any time. No such amendment or termination, however, shall alter or otherwise
affect the terms and  conditions  of any Loan then  outstanding  to Key Employee
without such Key Employee's written consent, except as otherwise provided herein
or in the promissory note evidencing such Loan.

SECTION 8. Miscellaneous Provisions.

      (a) No employee or other person shall have any claim or right to receive a
Loan under the Plan,  and no employee shall have any right to be retained in the
employ of the Company due to his or her participation in the Plan.

      (b) No Loan shall be made  hereunder  unless counsel for the Company shall
be satisfied that such Loan will be in compliance with applicable federal, state
and local laws.

      (c) The expenses of the Plan shall be borne by the Company.

      (d) The Plan shall be unfunded,  and the Company  shall not be required to
establish  any  special or  separate  fund or to make any other  segregation  of
assets to assure the making of any Loan under the Plan.

      (e) Except as otherwise  provided in Section 7 hereof,  by  accepting  any
Loan under the Plan,  each Key  Employee  shall be  conclusively  deemed to have
indicated his acceptance and  ratification  of, and consent to, any action taken
under  the  Plan or the  Stock  Holding  Policy  by the  Company,  the  Board of
Directors of the Company or the Committee.

      (f) The  appropriate  officers of the Company  shall cause to be filed any
reports,  returns or other  information  regarding  Loans  hereunder,  as may be
required by any applicable statute, rule or regulation.

SECTION 9. Effective Date.

      The Plan and the Stock Holding Policy shall become effective upon approval
and adoption by the Committee.


DOC # 1087
RGI STOCK HOLDING ASSISTANCE PLAN 5/98



<PAGE>


                         EXHIBIT A TO STOCK HOLDING ASSISTANCE PLAN


                         THE RANDERS GROUP INCORPORATED

                                 Promissory Note



$---------
Dated:____________


      For value  received,  ________________,  an individual  whose residence is
located at _______________________  (the "Employee"),  hereby promises to pay to
Thermo Ecotek  Corporation (the "Company"),  or assigns,  ON DEMAND,  but in any
case on or  before  [insert  date  which  is the  fifth  anniversary  of date of
issuance]  (the  "Maturity  Date"),  the principal sum of [loan amount in words]
($_______),  or such part  thereof as then  remains  unpaid,  without  interest.
Principal  shall be payable in lawful money of the United States of America,  in
immediately  available  funds, at the principal office of the Company or at such
other  place as the Company  may  designate  from time to time in writing to the
Employee.

      Unless the Company  has already  made a demand for payment in full of this
Note,  the Employee  agrees to repay to the Company from the  Employee's  annual
cash  incentive  compensation  (referred to as bonus),  beginning with the first
such bonus  payment to occur after the date of this Note and on each of the next
four bonus payment dates  occurring  prior to the Maturity Date,  such amount as
may be designated by the Company.  Any amount  remaining unpaid under this Note,
if no  demand  has been made by the  Company,  shall be due and  payable  on the
Maturity Date.

      This Note may be prepaid at any time or from time to time,  in whole or in
part, without any premium or penalty. The Employee  acknowledges and agrees that
the  Company has  advanced to the  Employee  the  principal  amount of this Note
pursuant to the Company's Stock Holding  Assistance Plan, and that all terms and
conditions of such Plan are incorporated herein by reference.

      The unpaid principal  amount of this Note shall be and become  immediately
due and payable without notice or demand, at the option of the Company, upon the
occurrence of any of the following events:

           (a) the  termination of the Employee's  employment  with the Company,
      with or without cause, for any reason or for no reason;

           (b)  the death or disability of the Employee;

           (c) the  failure  of the  Employee  to pay his or her  debts  as they
      become due, the  insolvency of the Employee,  the filing by or against the
      Employee of any petition under the United States  Bankruptcy  Code (or the
      filing  of  any  similar   petition   under  the  insolvency  law  of  any
      jurisdiction),  or the making by the  Employee of an  assignment  or trust
      mortgage for the benefit of creditors  or the  appointment  of a receiver,
      custodian  or  similar  agent with  respect  to, or the taking by any such
      person of possession of, any property of the Employee; or

           (d) the  issuance of any writ of  attachment,  by trustee  process or
      otherwise, or any restraining order or injunction not removed, repealed or
      dismissed  within  thirty (30) days of issuance,  against or affecting the
      person or property of the Employee or any  liability or  obligation of the
      Employee to the Company.

      In case any payment  herein  provided  for shall not be paid when due, the
Employee  further  promises  to pay  all  costs  of  collection,  including  all
reasonable attorneys' fees.

      No delay or omission on the part of the  Company in  exercising  any right
hereunder  shall  operate as a waiver of such right or of any other right of the
Company, nor shall any delay, omission or waiver on any one occasion be deemed a
bar to or waiver  of the same or any other  right on any  future  occasion.  The
Employee hereby waives presentment,  demand,  notice of prepayment,  protest and
all other  demands  and notices in  connection  with the  delivery,  acceptance,
performance, default or enforcement of this Note. The undersigned hereby assents
to any  indulgence  and any  extension  of time for payment of any  indebtedness
evidenced hereby granted or permitted by the Company.

      This Note has been made pursuant to the Company's Stock Holding Assistance
Plan and shall be governed by and  construed in accordance  with,  such Plan and
the  laws of the  State of  Delaware  and  shall  have  the  effect  of a sealed
instrument.


                               -------------------------------

                               Employee Name: _________________


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Witness