Experts-Conseil                     3172 Joseph Duebreuil
RTC                                 Lachine, Quebec H8T  3H5
Consulting                          (514) 636-3195 / fax (514) 636-5664
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                                                    April 7, 1997

3143619 CANADA INC.
TIREX CANADA
3767 Thimens Blvd.
Suite 207
St. Laurent, Quebec
H4R  1W4

ATTENTION:  MR. TERENCE C. BYRNE & MS. V.J. KACHRU
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Sirs:

         The intent of the present document is to outline our agreement with
respect to the scientific research and experimental developmental (hereinafter
"R&D") tax consultations to be provided to 3143619 Canada Inc. (hereinafter the
"Client") by RTC Consulting (hereinafter the "Consultant").

         1) The Consultant will attempt to maximize the 1996, 1997, 1998 and
2000 refundable investment tax credits (federal) and the R&D tax credits
(provincial) (hereinafter the "R&D tax credit claims"). The consultant will
perform the services as described in Annex A attached hereto, being the R&D
proposal dated March 25, 1997.

         2) The Client agrees to pay the Consultant ten percent (10%) of the
aggregate amount of the 1996, 1997, 1998, 1999 and 2000 R& D tax credit claims.

         3) All federal and provincial services taxes (GST and QST) are not
included in the Consultant's fees. They will be added to all amounts invoiced.

         4) The percentage of the tax credit refunds as stipulated hereinafter
will be paid by the Client to the Consultant on the earlier of the two following
dates: I) either the day that the Client's banking institution advances funds to
the Client based on the R&D claims directly or through loan guarantees by SDI,
or ii) when the credits are received form each of the two governments.

         5) The parties agree that any assistance provided by the Client during
the preparation of the R&D claims or representations made to defend the R&D
credit claim during a subsequent audit will not in any way serve to reduce the
fees payable to the Consultant.

         6) Subject to the provisions in the following paragraph, he amount of
the credit refund shall be equal to the amount stated in the notice of
assessment or reassessment.

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Experts-Conseil
RTC
Consulting

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         7) For further clarity, "R&D tax credit claims" shall mean all
refundable investment tax credits and R&D tax credits, but shall exclude all
corporate income taxes, Quebec capital taxes, overdue deductions at source, Part
IV taxes, provincial and/or federal sales, goods and services taxes, including
any penalties and/or interest that maybe levied on any of the items listed in
the forgoing exclusions.

         8) The Client through Research Investment Planning Enr., with the
Consultant's assistance, shall prepare the science report to be submitted to
Revenue Canada and Revenue Quebec.

         9) Subject to the Client receiving the majority of the anticipated
credit refunds, it agrees to prepare and send a letter to the governments
involved commenting on the importance of the R&D tax credit program in its
corporate entity.

         10) All notices sent by registered mail will be considered validly
received five (5) working days after posting of same. All notices sent by
facsimile will be considered validly received on the same day as their
transmission. The parties have convened that the dispositions of these presents
must be governed and interpreted according to the laws applicable to the
Province of Quebec. The nullity of one or other of the articles in the present
agreement will not effectively nullify the other articles of this agreement
which will remain in effect and will bind the signing parties.

         11) Any dispute or litigation that could occur following or upon the
occasion of the present agreement will definitely be settled under the aegis of
the National and International Commercial Arbitration Center of Quebec by means
of arbitration and with the exclusion of the courts, in compliance with its
general business arbitration by-laws in effect at the time of the signature of
the present Agreement.

         12) The Consultant will review and, where deemed appropriate, prepare
the R&D tax related documentation including "Claim for SR & ED expenditures"
(T661), "Investment Tax Credits (corporations)" (T2038), selected portions of
the "Reconciliation of Net Income per Financial Statements with Net Income for
Income Tax Purposes" (T2S1), "Capital Cost Allowance Schedules" (T2S8), as well
as any other prescribed forms where the application of these items will have a
bearing on credit refund maximization.

         11) The parties acknowledge that they have required that this Agreement
and all related documents be prepared in English. Les parties reconnaissent
avoir exige que la presente convention et tous les documents connexes soient
rediges en anglais.

<PAGE>

Experts-Conseil
RTC
Consulting
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                           AND THE PARTIES HAVE SIGNED

                                                  3143619 CANADA INC.
                                                  TIREX CANADA

                                             Per  /s/ V.J. KACHRU
                                                  ------------------------------
                                                      V.J. Kachru



                                                      RTC CONSULTING

                                             Per  /s/ PETER KUSTEC
                                                  ------------------------------
                                                      Peter Kustec

                                             Signed on May 9, 1997