<PAGE>

                                       1

                                                                   EXHIBIT 10.28

                                                                      [JTC LOGO]
                                                                     CORPORATION

PLEASE QUOTE OUR REFERENCE WHEN REPLYING
OUR REF: JTC(L) 3729/199 TEMP 9

28 APRIL 2004                                           JTC CORPORATION
                                                        The JTC Summit
TRIO-TECH INTERNATIONAL PTE LTD                         B Jurong Town Hall Road
1008 TOA PAYOH NORTH                                    Singapore 609434
#03-09
SINGAPORE(318996)                                       telephone (65) 6560 0056
                                                        facsimile (65) 6565 5301
                                                        web site  www.jtc.gov.sg

                                                        REGISTERED
(ATTENTION : BETTY YANG)

Dear Sirs

OFFER OF TENANCY FOR FLATTED FACTORY SPACE AT UNIT #03-08/09/10, BLK 1004, TOA
PAYOH NORTH, TOA PAYOH NORTH INDUSTRIAL ESTATE SINGAPORE 318995

1.    Thank you for your letter of acceptance dated 26 MARCH 2004 payment of
      $3689.15 and your Banker's Guarantee. We enclose the ORIGINAL STAMPED
      LETTER OF ACCEPTANCE for your retention. Kindly address all future
      correspondence concerning rental and other charges directly to:

      JTC CORPORATION
      THE JTC SUMMIT
      8 JURONG TOWN HALL ROAD
      SINGAPORE 609434
      ATTN: BILLING & COLLECTION SECTION
            CUSTOMER SERVICES GROUP
      TEL: 1800-5687000                        FAX:68855907

2.    Please submit the required plans as tabulated below for the approval and
      endorsement in accordance with our offer of tenancy dated 22 MARCH 2004.

<TABLE>
<CAPTION>
 PLANS/ DOCUMENTS                         CONTACT PERSON/
TO BE SUBMITTED BY                       TELEPHONE NO FOR
 YOUR COMPANY          DEPARTMENT      ENQUIRY/CLARIFICATION    REMARKS
 ------------          ----------      ---------------------    -------
<S>                    <C>             <C>                      <C>
 -  Type of plans       BUILDING          Mr Foo See Keong       Engage
 -  Factory             CONTROL UNIT      Tel 688551 69          registered
    layout              JTC                                      consultants for
                        8 Jurong
                        Town Hall
                        Road
                        Singapore
                        609434
                        (Relevant
                        JTC's
                        contacts are
                        given in para
                        4 below)
</TABLE>


<PAGE>

                                       3

                                                                      [JTC LOGO]

3.    We would appreciate it if you could inform us of your latest corresponding
      address, telephone and facsimile numbers.

4.    If you encounter any problems during your tenancy, please contact myself
      or MR LIM TIAN SIONG (ASSISTANT MANAGER LEASE MANAGEMENT) at Tel No.
      68833717.

Yours Faithfully

/s/ YEW PONG LOH
----------------
YEW PONG LOH

INDUSTRIAL DEVELOPMENT (HIGH-RISE) DEPARTMENT
INDUSTRIAL PARKS DEVELOPMENT GROUP
JTC CORPORATION

DID      :  68833411
FAX      :  68855901
Email    :  YEWPONG@JTC.GOV.SG

Attd: 1) Original Stamped letter of acceptance

<PAGE>

[TRIO-TECH LOGO]                     TRIO-TECH                       LOS ANGELES
                                   INTERNATIONAL                     SAN JOSE
                                  PRIVATE LIMITED                    DUBLIN
                                                                     SINGAPORE
                                                                     PENANG
                                                                     BANGKOK

26 March 2004

Industrial Development (High-Rise) Department
JTC Corporation                                      Stamp duty accounted to
The JTC Summit                                   Commissioner of Stamp Duties on
8 Jurong Town Hall Road                                    23 APR 2004
Singapore 609434                                     Jurong Town Corporation

Attn : Loh Yew Pong

ACCEPTANCE OF OFFER OF TENANCY FOR THE PREMISES AT UNIT 03-08/09/10 BLK 1004
TOA PAYOH NORTH TOA PAYOH NORTH INDUSTRIAL ESTATE SINGAPORE 318995

We refer to your letter of offer dated 22 March 2004 for the Tenancy and hereby
confirm our acceptance of all the covenants, terms and conditions of the Offer.

We are currently on GIRO, thus we enclose herewith a cheque for the amount of
$3689.15 and a Banker's/Insurance Guarantee for the amount of S$3216.33 (1
month's rental and service charge) as security deposit as confirmation of our
acceptance.

                                                    /s/ Lee Siew Kuan
--------------------------------------------------------------------------
Name of authorized signatory               :         Mrs Lee Siew Kuan
Designation                                :         Director of Logistics

For and on behalf of
TRIO-TECH INTERNATIONAL PTE LTD
In the presence of

                                                    /s/ Betty Ang
---------------------------------------------------------------------
Name of witness                            :        Ms Betty Ang
NRIC No.                                   :        S6945849A

[ ] REGIONAL HEAD OFFICE : 1008 Toa Payoh North #03-09 Singapore 318996
    Tel: 62653300 Fax: 62596355

<PAGE>

                                        1

                                                                     [ILLEGIBLE]

                                                                      [JTC LOGO]
                                                                     CORPORATION
PLEASE QUOTE OUR REFERENCE WHEN REPLYING
OUR REF: JTC(L) 3729/199 TEMP 9

22 MARCH 2004                                    JTC CORPORATION
                                                 The JTC Summit
                                                 8 Jurong Town Hall Road
                                                 Singapore 609434

                                                 customer
TRIO-TECH INTERNATIONAL PTE LTD                  service hotline  1800  568 7000
5 KIAN TECK ROAD                                 main line        (65) 6560 0056
SINGAPORE(628765)                                facsimile        (65) 6565 5301
                                                 website          www.jtc.gov.sg

                                                 BY LOCAL URGENT MAIL

(ATTENTION : BETTY YANG)

Dear Sirs,

OFFER OF TENANCY FOR FLATTED FACTORY SPACE

1     We are pleased to offer a tenancy of the Premises subject to the
      covenants, terms and conditions in the annexed Memorandum of Tenancy No.
      27.09 ("the MT") and in this letter (collectively called "the Offer").

2.    2.1   THE PREMISES:

            Private Lot A0618403 also known AS Unit #03-08/09/10 ("the
            Premises") in BLK 1004 TOA PAYOH NORTH ("the Building") in the TOA
            PAYOH NORTH INDUSTRIAL ESTATE SINGAPORE 318995 as delineated and
            edged in red on the plan attached to the Offer.

      2.2   TERM OF TENANCY:

            3 years ("the Term") with effect from 1 JUNE 2004 ("the Commencement
            Date").

<PAGE>

                                        2

                                                                      [JTC LOGO]

      2.3   TENANCY:

            (a)   Your due acceptance of the Offer in accordance with Clause 3
                  of this letter shall, together with the Offer, constitute a
                  binding tenancy agreement ("the Tenancy").

            (b)   In the event of any inconsistency or conflict between any
                  covenant, term or condition of this letter and the MT, the
                  relevant covenant, term or condition in this letter shall
                  prevail.

      2.4   AREA:

            Approximately 274.9 SQUARE METRES ("the Area").

      2.5   RENT:

            DISCOUNTED RENT

            (a)   Discounted rate of Dollars $9.45 per square metre per month on
                  the Area, for so long as you shall occupy by way of tenancy an
                  aggregate floor area of 5,000 to 9,999 square metres in the
                  Building or in the various flatted factories belonging to us;
                  and

            (b)   Normal rate of Dollars $9.95 per square metre per month on the
                  Area, in the event that the said aggregate floor area occupied
                  is at any time reduced to below 1,000 square metres (when the
                  discount shall be totally withdrawn) with effect from the date
                  of reduction in the said aggregate floor area,

                  2nd-tier discount rebate 5%

                  ("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.). After your first payment
                  is made in accordance with Clause 3 of this letter and the
                  attached Payment Table, the next payment shall be made on 01
                  JULY 2004.

      2.6   SERVICE CHARGE:

            $2.25 PER SQUARE METRE PER MONTH ("Service Charge") on the Area as
            charges for services rendered by us, payable by way of additional
            and further rent without demand on the same date and in the same
            manner as the Rent, subject to our revision from time to time.

<PAGE>

                                        3

                                                                      [JTC LOGO]

      2.7   SECURITY DEPOSIT/BANKER'S GUARANTEE:

            Ordinarily we would require a tenant to lodge with us a security
            deposit equivalent to THREE (3) MONTHS' rent and service charge.
            However, as an off-budget measure and as payment by GIRO has been
            made a condition with which you must comply under clause 3 of this
            letter, you shall, at the time of your acceptance of the Offer,
            place with us a deposit equivalent to ONE (1) MONTH'S Rent (at the
            discounted rate) and Service Charge ("Security Deposit") as security
            against any breach of the covenants, terms and conditions in the
            Tenancy, as follows:

            (a)   The Security Deposit may be in the form of cash or acceptable
                  Banker's Guarantee in the form attached (effective from 1
                  APRIL 2004 to 31 AUGUST 2007), or such other form of security
                  as we may in our absolute discretion permit or accept.

            (b)   The Security Deposit shall 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.

            (c)   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 shall immediately pay the
                  amount of such increase or make good the deductions so that
                  the Security Deposit shall at all times be equal to ONE (1)
                  MONTH'S Rent (at the normal or discounted rate, as the case
                  may be) and Service Charge.

            (d)   If at any time during the Term, your GIRO payment is
                  discontinued, then you shall place with us, within two (2)
                  weeks of the date of discontinuance of your GIRO payment, the
                  additional sum equivalent to TWO (2) MONTHS' Rent and Service
                  Charge, so that the Security Deposit shall at all times be
                  equal to three (3) months' Rent (at the normal or discounted
                  rate, as the case may be) and Service Charge for the remaining
                  period of the Term.

<PAGE>

                                        4

                                                                      [JTC LOGO]

            (e)   If at any time during the Term the off-budget measure is
                  withdrawn you shall, if required in writing by us, also pay to
                  us the additional sum equivalent to TWO (2) MONTHS' Rent and
                  Service Charge, so that the Security Deposit shall at all
                  times be equal to THREE (3) MONTHS' Rent (at the normal or
                  discounted rate, as the case may be) and Service Charge for
                  the remaining period of the Term.

      2.8   MODE OF PAYMENT:

            (a)   Your first payment to be made with your letter of acceptance
                  in accordance with Clause 3 of this letter and the attached
                  Payment Table shall be by non-cash mode (eg, Cashier's Order,
                  cheque).

            (b)   Thereafter during the Term, you shall pay Rent, Service Charge
                  and GST by Interbank GIRO or any other mode to be determined
                  by us.

            (c)   You have an existing account with us from which we shall
                  deduct the aforesaid payments. You are therefore not required
                  to submit a duly completed GIRO form as part of the Mode of
                  Due Acceptance. But if you wish to have a separate GIRO
                  account to meet the aforesaid payments, please complete the
                  GIRO deduction form enclosed.

      2.9   AUTHORISED USE:

            You shall use the Premises for the purpose of MANUFACTURE OF
            SEMICONDUCTOR ASSEMBLY AND TESTING EQUIPMENT. only and for no other
            purpose whatsoever ("the Authorised Use").

      2.10  APPROVALS:

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

<PAGE>

                                        5

                                                                      [JTC LOGO]

      2.11  POSSESSION OF PREMISES:

            (a)   Subject to your acceptance of the Offer, keys to the Premises
                  shall be made available to you within the period of two (2)
                  months prior to the Commencement Date.

            (b)   From the date you accept the keys to the Premises ("Possession
                  Date") until the Commencement Date, you shall be deemed a
                  licensee upon the same covenants, terms and conditions as in
                  the Tenancy.

            (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:

                  (c1)  remove everything installed by you;

                  (c2)  reinstate the Premises to its original state and
                        condition; and

                  (c3)  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.

      2.12  LOADING CAPACITY:

            (a)   NORMAL (GROUND & NON-GROUND) FLOOR PREMISES:

                  You shall comply and ensure compliance with the following
                  restrictions:

                  (a1)  maximum loading capacity of the goods lifts in the
                        Building; and

                  (a2)  maximum floor loading capacity of 15 kiloNewtons per
                        square metre of the Premises on the 03 storey of the
                        Building PROVIDED THAT any such permitted load shall be
                        evenly distributed.

<PAGE>

                                        6

                                                                      [JTC LOGO]

      2.13  OPTION FOR RENEWAL OF TENANCY:

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

            (b)   We may grant you a further term of tenancy of the Premises
                  subject to the following:

                  (b1)  there shall be no breach of your obligations at the time
                        you make your request for a further term, and at the
                        expiry of the Term;

                  (b2)  the duration of the further term shall be mutually
                        agreed upon;

                  (b3)  the rent payable shall be at a revised rate to be
                        determined by us, having regard to the market rent of
                        the Premises at the time of granting the further term.
                        Our determination of the rent shall be final and
                        conclusive; and

                  (b4)  the tenancy for the further term shall be upon the same
                        covenants, terms and conditions except for the duration,
                        rent, security deposit (which shall be equivalent to
                        three (3) month's rent and service charge instead of two
                        (2) months), and excluding a covenant for renewal of
                        tenancy.

3     MODE OF DUE ACCEPTANCE:

      The Offer shall lapse if we do not receive the following by 31 MARCH 2004:

      (a)   Duly signed letter of acceptance (IN DUPLICATE) of the Offer, in the
            form set out in the LETTER OF ACCEPTANCE attached. (PLEASE DATE AS
            REQUIRED IN YOUR LETTER OF ACCEPTANCE)

      (b)   Payment of the sum set out in the PAYMENT TABLE attached.

      (c)   Duly completed GIRO authorization form.

<PAGE>

                                        7

                                                                      [JTC LOGO]

4.    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 those 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.

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 2.11(c) of this letter.

6     VARIATION TO THE TENANCY:

      Any variation, modification, amendment, deletion, addition or otherwise of
      the Offer shall not be enforceable unless agreed by both parties and
      reduced in writing by us. No terms or representation or otherwise, whether
      expressed or implied, shall form part of the Offer other than what is
      contained herein.

7     CAR-PARKING SCHEME:

      The carpark for BLK 1004 TOA PAYOH NORTH is currently managed by P-PARKING
      INTERNATIONAL PTE LTD and you will have to observe and be bound by all the
      rules and regulations governing the use and operation of the carpark. You
      are requested to contact:

                                736B GEYLANG ROAD
                                 SINGAPORE 389647
                                  TEL: 67494119
                                  FAX: 67493689

      on your use of the carpark.

<PAGE>

                                        8

                                                                      [JTC LOGO]

8     ELECTRICITY CONNECTION:

      Upon your acceptance of the Offer, you are advised to proceed
      expeditiously to 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 of
      our Customer Services Group at 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, therefore, contact the Property Support Department at #05-01 Blk
      25 Kallang Avenue, Kallang Basin Industrial Estate Singapore 339416 direct
      for their requirements.

9     To guide and assist you, we enclose a SCHEDULE OF STATUTORY CONTROLS for
      Flatted Factory Occupants.

Yours faithfully

/s/ YEW PONG LOH
----------------
YEW PONG LOH

INDUSTRIAL DEVELOPMENT (HIGH-RISE) DEPARTMENT
INDUSTRIAL PARKS DEVELOPMENT GROUP
JTC CORPORATION
DID: 68833411
FAX: 68855901
Email: YEWPONG@JTC.GOV.SG

ENCS:

[x] Payment Table                 [x] GIRO Form(s)        [x] Specimen BG Plan

[x] Specimen Acceptance Form      [x] MT No. 27.09

[x] Schedule of Statutory Controls (SC2)]

<PAGE>

                                        9

                                                                      [JTC LOGO]

                                  PAYMENT TABLE

PREMISES: PRIVATE LOT A0618403 UNIT #03/08/09/10 BLK 1004 TOA PAYOH NORTH TOA
PAYOH NORTH INDUSTRIAL ESTATE SINGAPORE 628765

<TABLE>
<CAPTION>
                                                        AMOUNT                       +5% GST
                                                ----------------------               -------
<S>                                             <C>            <C>                   <C>
Rent at $9.45 per square metre per
month on 274.9 square metres for
the period 1 JUNE 2004 to 30 JUNE
2004                                            $2597.81                             $129.89

$2.25 per square metre per month on
274.9 square metres for the period
1 JUNE 2004 to 30 JUNE 2004                     $ 618.53                             $ 30.93

Total Rent Payable (inclusive of
Service Charge)                                                $3216.33              $160.82

SECURITY DEPOSIT equivalent to
three (3) months' Rent and Service
Charge (in cash or Banker's
Guarantee provided in accordance
with Clause 2.7 of this letter)                 $9648.99

Less:
Equivalent of two (2) month's Rent
and Service Charge (re Off-budget
Measure and GIRO)                               $6432.66       $3216.33
</TABLE>

<PAGE>

                                       10

                                                                      [JTC LOGO]

<TABLE>
<S>                                             <C>            <C>                   <C>
STAMP FEE payable on Letter
of Acceptance (which we will
stamp on your behalf)

Note: If the Letter is not
returned to us within 14 days of
the date of the Letter, you will have
to pay penalty on the stamp duty which
is imposed by Stamp Duty Office of IRAS.                       $ 312.00

Sub-Total Payable                                              $6744.66              $160.82

ADD: GST @ 5%                                                  $ 160.82

Total Payable inclusive of GST                                 $6905.48
</TABLE>

<PAGE>

[TRIO-TECH LOGO]                     TRIO-TECH                       LOS ANGELES
                                   INTERNATIONAL                     SAN JOSE
                                  PRIVATE LIMITED                    DUBLIN
                                                                     SINGAPORE
                                                                     PENANG
                                                                     BANGKOK

26 March 2004

Industrial Development (High-Rise) Department
JTC Corporation
The JTC Summit
8 Jurong Town Hall Road
Singapore 609434

Attn : Loh Yew Pong

ACCEPTANCE OF OFFER OF TENANCY FOR THE PREMISES AT UNIT 03-08/09/10 BLK 1004
TOA PAYOH NOBTH TOA PAYOH NORTH INDUSTRIAL ESTATE SINGAPORE 318995

We refer to your letter of offer dated 22 March 2004 for the Tenancy and hereby
confirm our acceptance of all the covenants, terms and conditions of the Offer.

We are currently on GIRO, thus we enclose herewith a cheque for the amount of
$3689.15 and a Banker's/Insurance Guarantee for the amount of S$3216.33 (1
month's rental and service charge) as security deposit as confirmation of our
acceptance.

                                                    /s/ Lee Siew Kuan
-------------------------------------------------------------------------
Name of authorized signatory                :       Mrs Lee Siew Kuan
Designation                                 :       Director of Logistics

For and on behalf of
TRIO-TECH INTERNATIONAL PTE LTD
In the presence of

                                                    /s/ Betty Ang
------------------------------------------------------------------------
Name of witness                             :       Ms Betty Ang
NRIC No.                                    :       S6945849A

[ ] REGIONAL HEAD OFFICE : 1008 Toa Payoh North #03-09 Singapore 318996
    Tel: 62653300 Fax: 62596355
<PAGE>


                              [THE GMP GROUP LOGO]

               5% rebate granted! See page 2 of Letter of Offer.

                               www.gmprecruit.com
             1 Scotts Road #22-01/03 Shaw Centre, Singapore 228208
          Tel: 6736 2022 - Fax: 6736 2155 - Email: info@gmprecruit.com

<PAGE>

                                              SPECIMEN BANK'S/FINANCE COMPANY'S/
                                              INSURANCE COMPANY'S GUARANTEE FORM

                                    GUARANTEE
                       (Please use guarantor's letterhead)

 TO: JTC CORPORATION
     THE JTC SUMMIT
     8 JURONG TOWN HALL ROAD
     SINGAPORE 609434

WHEREAS:

[TRIO-TECH INTERNATIONAL PTE LTD] of [5 KIAN TECK ROAD - SINGAPORE 628765] ("the
Tenant") is a tenant of the premises known as [UNIT #03-08/09/10 BLK 1004 TOA
PAYOH NORTH TOA PAYOH NORTH INDUSTRIAL ESTATE SINGAPORE 318995] ("the Premises")
pursuant to a letter of offer dated [22 MARCH 2004] from you to and duly
accepted by the Tenant ("the Tenancy", which expression shall include any
written amendments made to the Tenancy from time to time).

IN CONSIDERATION OF your agreeing to grant the Tenancy and pursuant to a term of
the Tenancy, we, the undersigned, hereby unconditionally undertake to pay to you
from time to time on first demand the sum or aggregate sums not exceeding
[$___________] ("the Full Guaranteed Sum") if accompanied by your statement that
the Tenant is in breach of any of the Tenant's Obligations to you under the
Tenancy and that the amount demanded is due and payable to you and remains
unpaid Provided That our liability under this Guarantee shall not exceed the
Full Guaranteed Sum.

Our liability under this Guarantee shall be that of a principal debtor and not
by way of surety and such liability shall not be discharged or affected by any
event, act or omission whereby our liability would have been discharged if we
had been a surety.

This Guarantee is valid from [1 APRIL 2004] and shall expire on [31 AUGUST 2007]
("the expiry date") and our liability hereunder shall cease in respect of any
claims made after the expiry date.

Notwithstanding that this Guarantee may not have expired, our liability
hereunder shall cease forthwith upon our paying to you the Full Guaranteed Sum
to be held by you as a security deposit under the Tenancy.

Date:____________________

[SIGNATURE, NAMES AND DESIGNATIONS OF AUTHORISED SIGNATORIES OF BANK/FINANCE
COMPANY/INSURANCE COMPANY AND RUBBER STAMP OF BANK/FINANCE COMPANY/INSURANCE
COMPANY]

BG(Security Deposit)/Tenancy/13.014/June 2002/Lg FF RV team