<PAGE>

                                                                   Exhibit 10.21

[LOGO]      TRIO-TECH
            INTERNATIONAL                                   LOS ANGELES
                                                            SINGAPORE
                                                            DUBLIN
                                                            PENANG
                                                            KUALA LUMPUR
                                                            BANGKOK

10 November 2000

Mr Teo Soon Siang                                    BY HAND
Marketing & Sales Department                         -------
Jurong Town Corporation
The JTC Summit
8 Jurong Town Hall Road
Singapore 609434

Dear Mr Teo Soon Siang


ACCEPTANCE OF OFFER OF TENANCY FOR THE PREMISES AT BILK 1008 TOA PAYOH NORTH
#07-01 TOA PAYOH INDUSTRIAL ESTATE SINGAPORE 318996

1.   We refer to your letter of offer dated 30 October 2000 for the Tenancy and
     hereby confirm our acceptance of all the covenants, terms and conditions
     stipulated therein.

2.   We enclose herewith a cheque for the amount of S$4831.02 and the Banker's
     Guarantee as security deposit as confirmation of our acceptance.

3.   In addition, we also enclose herewith a duly completed GIRO authorisation
     form.


                                            By: /s/ Lee Siew Kuan
-----------------------------------------------------------------------------
Name of authorised signatory    :           Mrs Lee Siew Kuan
Designation                     :           Director of Logistics
For and-On behalf of            :           Trio-Tech International Pte Ltd

In the presence of



                                            By: /s/ Betty Ang
-----------------------------------------------------------------------------
Name of witness                 :           Miss Betty Ang
NRIC No.                        :           S6945849A
<PAGE>

JTC(L)3601/2606 Temp 3
                                             DID: 8833427
                                             FAX:8855899
                                             Email: chenwan@jtc.gov.sg
30 October 2000                                                     JTC


TRIO-TECH INTERNATIONAL PTE LTD
Blk 1008 Toa Payoh North
#03-09/15
Singapore 318996
                                             BY LUM
                                             ------
(Attn: Ms Betty Ang)


Dear Sirs,

OFFER OF TENANCY FOR FLATTED FACTORY SPACE

1.   We are pleased to offer a tenancy of the Premises subject to the following
     covenants, terms and conditions in this letter and in the annexed
     Memorandum of Tenancy ("the Offer"):

     1.01  Location:

           Pte Lot A19597(f), Blk 1008 ("the Building") Toa Payoh North #07-01,
           Toa Payoh Industrial Estate Singapore 318996 ("the Premises") as
           delineated and edged in red on the plan attached to the Offer.

     1.02  Term of Tenancy:

           3 years ("the Term") with effect from 16 January 2001 ("the
           Commencement Date").

     1.03  Tenancy Agreement:

           Upon due acceptance of the Offer in accordance with clause 2 of this
           letter, you shall have   entered into a tenancy agreement with US
           ("the Tenancy") and will be bound by the covenants, terms and
           conditions thereof.

           In the event of any inconsistency or conflict between any covenant,
           term or condition of this letter and the Memorandum of Tenancy, the
           relevant covenant, term or condition in this letter shall prevail.

     1.04  Area:

           Approximately 322.00 square metres (subject to survey).
<PAGE>

                                              Jurong Town Corporation
     1.05 Rent and Service Charge:

          Rent:
          ----

          (a)   Discounted rate of Dollars $11.54 per square metre per month for
                so long as the Tenant shall occupy by way of tenancy an
                aggregate floor area of 1000 square metres in the Building or in
                the various flatted factories belonging to the Landlord, and

          (b)   Normal rate of Dollars $11.90 per square metre per month in the
                event that the said aggregate floor area occupied is at any time
                reduced to below 1000 square metre (when the discount shall be
                totally withdrawn) with effect from the date of reduction in the
                said aggregate floor,

          ("Rent") to be paid without demand and in advance without deduction
          on the 1st day of each month of the year (i.e. 1st of January,
          February, March, etc.). The next payment shall be made on 1 February
          2001.

          Service charge:
          ---------------

          $2.10 per square metre per month, ("Service Charge") as charges for
          services rendered by us, payable without demand on the same date and
          in the same manner as the Rent, subject to our revision from time to
          time.

     1.06 Security Deposit/Banker's Guarantee:

          You will at the time of acceptance of the Offer be required to place
          with us a deposit of Dollars $13,176.24 equivalent to 3 months' Rent
          (at the discounted rate) and Service Charge ("Security Deposit") as
          security against any breach of the covenants, terms and conditions in
          the Tenancy.

          The Security Deposit may be in the form of cash and/or acceptable
          Banker's Guarantee in the form attached (effective from 16 November
          2000 to 15 July 2004 ) and/or such other form of security as we may in
          our absolute discretion permit or accept.

          The Security Deposit must be maintained at the same sum throughout the
          Term and shall be repayable to you without interest or returned to you
          for cancellation, after the termination of the Term (by expiry or
          otherwise) or expiry of the Banker's Guarantee, as the case may be,
          subject to appropriate deductions or payment to us for damages or
          other sums due under the Tenancy.
<PAGE>

                                              Jurong Town Corporation

          If the Rent at the discounted rate is increased to the normal rate or
          Service Charge is increased or any deductions are made from the
          Security Deposit, you are to immediately pay the amount of such
          increase or make good the deductions so that the Security Deposit
          shall at all times be equal to 3 months' Rent and Service Charge.

     1.07 Mode of Payment:

          [Note: You have an existing account with us from which we will deduct
          -------
          the aforesaid payments. You are therefore not required to submit a
          duly completed GIRO form as part of the Mode of Acceptance herein
          unless you wish to have a separate GIRO account to meet the aforesaid
          payments.]

     1.08 Permitted Use:

          (a)    Subject to clause 1.12 of this letter, you shall commence full
                 operations within four (4) months of the Commencement Date for
                 the purpose of IC testing only and for no other purpose
                 whatsoever ("the Authorised Use").

          (b)    Thereafter, you shall maintain full and continuous operations
                 and use and occupy the whole of the Premises for the Authorised
                 Use.

          (c)    Subject to clauses (a) and (b) above, you shall use and occupy
                 at least sixty percent (60%) of the gross floor area of the
                 Premises for industrial activities and ancillary stores, and
                 use and occupy the remaining gross floor area, if any, for
                 offices, neutral areas, communal facilities and such other uses
                 as may be approved in writing by us and the relevant
                 governmental and statutory authorities PROVIDED THAT you shall
                 not use and occupy the Premises for the purpose of commercial
                 office and storage unrelated to the Authorised Use.

     1.09 Approvals

          The Tenancy is subject to approvals being obtained from the relevant
          government and statutory authorities.

     1.10 Possession of Premises:

          (a)    Keys to the Premises will be given to you two (2) months prior
                 to the Commencement Date subject to due acceptance of the Offer
                 ("Possession Date").

          (b)    From the Possession Date until the Commencement Date, you shall
                 be deemed a licensee upon the same terms and conditions in the
                 Tenancy.
<PAGE>

                                              Jurong Town Corporation

     (c)  if you proceed with the Tenancy after the Commencement Date, the
          licence fee payable from the Possession Date to the Commencement Date
          shall be waived ("Rent-Free Period"). Should you fail to so proceed,
          you shall

          (i)    remove everything installed by you;
          (ii)   reinstate the Premises to its original state and condition;
                 and
          (iii)  pay us a sum equal to the prevailing market rent payable for
                 the period from the Possession Date up to the date the
                 installations are removed and reinstatement completed to our
                 satisfaction,

          without prejudice to any other rights and remedies we may have against
          you under the Tenancy or at law.

1.11 Preparation and Submission of Plans:

     (a)  No alteration, addition, improvement, erection, installation or
          interference to or in the Premises or the fixtures and fittings
          therein is permitted without Building Control Unit [BCU(JTC)] prior
          written consent. Your attention is drawn to clauses 2.10 to 2.19 and
          2.34 of the Memorandum of Tenancy.

     (b)  You will be required to prepare and submit floor layout plans of your
          factory and plans of the air-conditioning works in accordance with the
          terms of the tenancy and the 'Guide' attached. It is important that
          you should proceed with the preparation and submission of the plans in
          accordance with the procedures set out in the said 'Guide.

     (c)  Should there be alteration of existing automatic fire alarm and
          sprinkler system installation, alteration plans shall be submitted to
          Building Control Unit [BCU(JTC)] for approval on fire safety aspects.
          All air-conditioning, fire alarm & sprinkler system plans must be
          signed by a relevant Professional Engineer, registered with the
          Professional Engineers Board of Singapore.

     (d)  Upon due acceptance of the Offer, a copy of the floor and elevation
          plans (transparencies) will be issued to you to assist in the
          preparation of the plans required herein.

     (e)  No work shall commence until the plans have been approved by Building
          Control Unit [BCU(JTC)].
<PAGE>

                                                   Jurong Town Corporation

     1.12  Final inspection:

     You shall ensure that final inspection by us of all installations is
     carried out and our approval of the same is obtained before any operations
     in the Premises may be commenced.

     1.13  Special Conditions:

     (1)  Normal (Ground & Non-ground) Floor Premises
          -------------------------------------------

          You shall comply and ensure compliance with the following
          restrictions:

          (a)  maximum loading capacity of the goods lifts in the Building; and

          (b)  maximum floor loading capacity of 10.00 kiloNewtons per square
               metre of the Premises on the 7th storey of the Building PROVIDED
               THAT any such permitted load shall be evenly distributed.

          We shall not be liable for any loss or damage that you may suffer from
          any subsidence or cracking of the ground floor slabs and aprons of the
          Building.

     (2)  Option for renewal of tenancy
          -----------------------------

          (a)  You may within 3 months before the expiry of the Term make a
               written requet to us for a further term of tenancy.

          (b)  We may grant you a further term of tenancy of the Premises upon
               mutual terms to be agreed between you and us subject to the
               following:

               (i)    there shall be no breach of your obligations at the you
                      make your request for a further term; time

               (ii)   our determination of revised rent, having regard to market
                      rent of the Premises at the time of the granting the
                      further term, shall be final;
               (iii)  we shall have absolute discretion to determine such
                      covenants, terms and conditions, but excluding a covenant
                      for renewal of tenancy; and
               (iv)   there shall not be any breach of your obligations expiry
                      of the Term.
<PAGE>

                                                   Jurong Town Corporation

2.  Mode of Acceptance:

    The Offer shall lapse if we do not receive the following by 13 November
    2000:-

    .  Duly signed letter of acceptance (in duplicate) of all the covenants,
       terms and conditions in the Tenancy in the form enclosed at the
       Appendix. (Please date as required in the Appendix)

    .  Payment of the sum set out in clause 4.

    .  Duly completed GIRO authorization form.

3.  Please note that payments made prior to your giving us the other items
    listed above may be cleared by and credited by us upon receipt. However, if
    the said other items are not forthcoming from you within the time stipulated
    herein, the Offer shall lapse and there shall be no contract between you and
    us arising hereunder. Any payments received shall then be refunded to you
    without interest and you shall have no claim of whatsoever nature against
    us.

4.  The total amount payable is as follows:

--------------------------------------------------------------------------------
                                            Amount                      +3 % GST
--------------------------------------------------------------------------------
Rent at $11.54 psm per month on
322.00 sq m for the period 16 January
2001 to 15 February 2001                   $3,715.88
--------------------------------------------------------------------------------
Less:
--------------------------------------------------------------------------------
3% property tax rebate on rental value     $  111.48
                                           ---------
                                           $3,604.40
--------------------------------------------------------------------------------
Service Charge at $2.10 psm per
month on 322.00 sq m for the period
16 January 2001 to 15 February 2001        $  676.20     $ 4,280.60      $128.42
                                           ---------
--------------------------------------------------------------------------------
Deposit equivalent to three months'
rent and service charge (or Banker's
Guarantee provided in accordance with
sub-paragraph 1.06 above)                                $13,176.24
--------------------------------------------------------------------------------
Stamp fee payable on Letter of
Acceptance which will be stamped by
JTC on your behalf                                       $   422.00
--------------------------------------------------------------------------------
Sub-Total Payable                                        $17,878.84      $128.42
--------------------------------------------------------------------------------
Add: GST + 3%                                            $   128.42
--------------------------------------------------------------------------------
Total Amount Payable                                     $18,007.26
--------------------------------------------------------------------------------
<PAGE>

                                                   Jurong Town Corporation

5.  Rent-Free Period:

    As the Commencement Date will not be deferred, we advise you to accept the
    Offer as soon as possible and to collect the keys to the Premises on the
    scheduled date in order to maximize the Rent-Free Period referred to in
    clause 1.10(c) of this letter.

6.  Variation to the Tenancy

    This letter and the Memorandum of Tenancy constitute the full terms and
    conditions governing the Offer and no terms or representation or otherwise,
    whether express or implied, shall form part of the Offer other than what is
    contained herein. Any variation, modification, amendment, deletion, addition
    or otherwise of the covenants, terms and conditions of the Offer shall not
    be enforceable unless agreed by both parties and reduced in writing by us.

7.  Car-Parking Scheme:
    (a)  The car park for Blk 1008 Toa Payoh North is currently managed by
         Wilson Parking (S) Pte Ltd and you will have to observe and be bound by
         all the rules and regulations governing the use and operation of the
         car park. You are requested to contact the following person on the use
         of the car park:

         Ms Susan Ng
         Wilson Parking (S) Pte Ltd
         32 Sultan Gate
         Singapore 198480
         Tel No:2966600

         a member of the Committee, on your use of the car park.

    (b)  The Corporation shall not be liable for any loss, damage, injury,
         liability, claim or action you may sustain or suffer in the use of the
         car park and the tenants shall fully indemnify the Corporation against
         any loss, claims, penalties, demands, damage arising from the private
         management and operations of the car park by the tenants.

8.  Application for Approvals, Utilities etc.

    Upon your acceptance of the covenants, terms and conditions of the Offer,
    you are advised to proceed expeditiously as follows:
<PAGE>

                                                   Jurong Town Corporation

8.01  Preliminary Clearance:

      Comply with the requirements of the Chief Engineer (Central Building Plan
      Unit), Pollution Control Department and/or other departments pursuant to
      your application/s for preliminary clearance. (Please note that we have
      referred your application to the relevant department/s)

8.02  Discharge of Trade Effluence:

      Complete the attached Application for Permission to Discharge Trade
      Effluent into Public Sewer and return the application form direct to the
      Head, Pollution Control Department, Ministry of Environment, Environment
      Building, 40 Scotts Road. Singapore 228231 (Telephone No. 7327733).

8.03  Electricity:

      Engage a registered electrical consultant or competent contractor to
      submit three sets of electrical single-line diagrams to and in accordance
      with the requirements of our Property Support Department (PSD), Customer
      Services Group, JTC East Zone Office for endorsement before an application
      is made to the Power Supply Pte Ltd to open an account for electricity
      connection. Please contact our Property Support Department (PSD) at Blk 25
      Kallang Avenue #05-01 Kallang Basin Industrial Estate Singapore 339416
      direct for their requirements.

8.04  Water:

      Submit four copies of sketch plans, prepared by a licensed plumber,
      showing the section and layout of the plumbing, to our Building Control
      Unit [BCU(JTC)] for approval prior to the issue of a letter to Water
      Conservation Department, Public Utilities Board to assist you in your
      application for a water sub-meter.

8.05  Telephone:

      Apply direct to Singapore Telecommunications Ltd for all connections.

8.06  Automatic Fire Alarm System ( Incorporating Heat Detector)

      Engage a registered electrical consultant/professional engineer to submit
      two sets of fire alarm drawings, indicating the existing fixtures if any,
      the proposed modifications of the fire alarm and the layout of machinery,
      etc to and in accordance with the requirements of our Building Control
      Unit [BCU(JTC)I. Please contact our Building Control Unit [BCU(JTC)] at
      The JTC Summit, Customer Service Centre (1st level) 8 Jurong Town Hall
      Road Singapore 609434 direct for further requirements.
<PAGE>

                                                   Jurong Town Corporation

8.07  Factory Inspectorate

      Complete and return direct to Chief Inspector of Factories the attached
      form, "Particulars to be submitted by occupiers or Intending Occupiers of
      Factories".


      Yours faithfully


      By: /s/ Jenny Lim

      JENNY LIM (Ms)
      MARKETING & SALES DEPARTMENT
      INDUSTRIAL PARKS DEVELOPMENT GROUP
      JURONG TOWN CORPORATION

      Encl