Document:

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                                                                    EXHIBIT 4.15

                             PRIVATE & CONFIDENTIAL

30 November 2001

Mr Harry H. Davoody
4401 Freemont Lane
Plano, TX75093

Dear Harry,

LETTER OF APPOINTMENT

1.   We are pleased to appoint you as the PRESIDENT & CHIEF EXECUTIVE OFFICER OF
     ST ASSEMBLY TEST SERVICES LTD (THE 'COMPANY'). You will be responsible to
     the Board of Directors for the overall profitability and growth of the
     company.

2.   REMUNERATION

     a.   Your will receive an annual base salary of US$300,000. Your service
          grade is G3.

     b.   Performance and salary review will be conducted annually on or about 1
          July each year. Annual salary increments are based on individual and
          company performances, in accordance with the policies approved by the
          Company's Executive Resource and Compensation Committee (ERCC) form
          time to time.

     c.   Please note that salary and bonus payments are made based on
          individual merits and should therefore be kept strictly confidential.

     d.   As G3 staff, your salary and other special terms will be administered
          personally by Cheo Hock Kuan (Ms), Secretary ERCC.

3.   OTHER GENERAL TERMS AND CONDITIONS

     Other general terms and conditions of your service are as described in
     ANNEX 1 attached.

4.   SPECIAL TERMS AND CONDITIONS

     Specific terms and conditions for your employment on a personal-to-holder
     basis are as described in ANNEX 2 attached.
<PAGE>
5.   ACCEPTANCE OF OFFER

     If you accept this offer of appointment, please sign and return the
     following to me:

     a.   Duplicate copy of this letter;
     b.   1 copy of Personal Particulars Form (include 2 passport photographs);
     c.   1 copy of Employees' Declaration and Undertaking;
     d.   1 copy of Bank Authorisation Form;
     e.   1 copy of Insurance Nominee Form.

6.   I look forward to welcoming you to STATS.

Yours sincerely,

/s/ Ho Ching
HO CHING
CHAIRMAN ERCC

cc
Cheo Hock Kuan (Ms)
Secretary ERCC

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I, Harry H. Davoody , NRIC /Passport No. US Passport # 131946624, having read
and understood the terms and conditions in the Letter of Appointment, hereby
accept the appointment on these terms and conditions, and confirm that I shall
commence work on early January 2002.

/s/ Harry H. Davoody                           December 4th, 2001
-------------------------                    -----------------------
        Signature                                     Date

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If you decline this offer, please return to us this letter and all enclosures.
If we do not hear from you within 2 weeks, this offer will lapse.
<PAGE>
                             PRIVATE & CONFIDENTIAL

     ANNEX 1 - GENERAL TERMS AND CONDITIONS OF SERVICE FOR G1 STAFF & ABOVE

1.   GENERAL TERMS & CONDITIONS OF SERVICE

     1.1. You shall not at any time during your service with the Company either
          directly or indirectly (without prior written consent from the
          Company) engage or interest yourself, whether for reward or
          gratuitously, in any work or business other than related to your
          duties in the Company.

     1.2. You shall devote with the whole of your time, knowledge, skill and
          attention in the performance of your duties in the Company, and attend
          at the premises where you shall from time to time be posted by the
          Company on such days including, if the exigencies of the work so
          require, on Sunday and public holidays and at such hours as may be
          required.

     1.3. You shall enjoy all other standard benefits and be subject to all
          conditions applicable to executives under your job grade.

     1.4. The Company reserves the right to vary the terms and conditions of
          service based on business needs from time to time.

     1.5. You will abide by the terms and conditions of service, the rates,
          regulations and procedures as may be laid down by the Company from
          time to time and the laws of the Republic of Singapore.

2.   WORKING HOURS

     2.1  Your working hours will be as per company policy.

     2.2  As a senior executive staff, you are expected to work beyond normal
          hours based on the exigencies of service without overtime claims.

3.   LEAVE

     3.1  You shall be eligible for 21 days of paid leave each year. Your leave
          administration will be as per the company's policy.
<PAGE>
4.   EMPLOYEE BENEFITS PROGRAM

     4.1  We have put in place a flexible benefits program for our senior
          employees. This program allows for freedom and flexibility to put
          together the benefit package which best suits your needs and that of
          your immediate family at different stages of your career. The flexible
          benefits brochure together with the enrolment instructions will be
          forwarded to you upon your acceptance of the appointment.

5.   CONFIDENTIALITY & SECRECY

     5.1  During the continuance of your employment with the Company and at all
          times after the termination of your employment from any cause
          whatsoever, you shall not directly or indirectly disclose, divulge,
          authorise or permit to be disclosed to anyone not properly entitled
          thereto any trade secrets, know-how and any confidential information
          relating to the business or financial conditions of the Company.

6.   TERMINATION OF SERVICE

     6.1  Termination can only be effected in writing by either party, without
          giving any reasons, by giving 3 months notice or the payment of a sum
          equivalent to 3 months' salary in lieu of notice.

     6.2  All staff benefits shall cease after the last day of service. Any
          money due and owing under any staff loan scheme, scholarships, bonds
          or otherwise payable by you to the Company must be settled before the
          last day of service. The Company reserves the right to offset any
          outstanding sum from the balance of money payable by the company to
          you.

     6.3  Notwithstanding conditions above, the Company reserves the right at
          all times to terminate your services forthwith if you should be guilty
          of misdemeanor, misconduct, negligence or breach of any of the terms
          of this offer or any other existing terms and conditions of service,
          rule or regulation laid down by the Company from time to time for all
          members of its staff.
<PAGE>
                             PRIVATE & CONFIDENTIAL

                     ANNEX 2 - SPECIAL TERMS AND CONDITIONS
                               (HARRY H. DAVOODY)

1.   SHARE OPTION

     1.1  It will be recommended to the ERCC that you be granted an option to
          purchase 4,000,000 Ordinary shares in the Employee Share Option Scheme
          (ESOS). The options granted will be priced at the fair market price on
          the day of your commencement with STATS. The fair market price
          computation will be as specified in the ESOS.

     1.2  The vesting period will be as follows:

          (a)  For the first 1,500,000 shares, the vesting period will be vested
               over 5 years as per the ESOS policy.

          (b)  For the second 1,500,000 shares, you will be allowed to vest them
               when the company's share price reaches S$3.60 for a continuous
               period of 20 days.

          (c)  For the final 1,000,000 shares, you will be allowed to vest them
               when the company's share prices reaches S$6.00 per share for a
               continuous period of 20 days.

     1.3  Additional grants are planned on annual basis, based upon individual
          and company performance.

     1.4  Other terms and conditions will be governed by the ESOS.

2.   GUARANTEED BONUS

For the financial years ending December 2002 and 2003, you will receive a
guaranteed bonus of US$300,000 on a pro-rated basis to the length of service.

3.   PERFORMANCE INCENTIVE

     3.1  You will be eligible to participate in the EVA-Based Incentive Plan
          from year 2002 onwards. For year 2002 and 2003, your EVA based
          incentive will be the summation of X & Y as given below:

          X (a % of EVA sharing)                               0/59%
          Y (a% of EVA improvement sharing )                   1.77%
<PAGE>
     3.2  The computation and the payout of the EVA incentives will be governed
          by the EVA Based Incentive Policy as attached.

     3.3  The above sharing plan will remain unchanged for 2002 and 2003 unless
          ERCC decides otherwise. You will be informed of any change at the
          start of each subsequent year.

     3.4  In addition, you will also be eligible to participate in the
          Performance Target Bonus which has a maximum of 2 1/2 months
          equivalent of bonus for achieving pre-determined targets aiming at
          organization and people development among other business targets for
          the year.

4.   CAR BENEFITS AND EXPENSES

     4.1  The company will provide you with a grant of S$230,000 over six(6)
          years for purchase of a car under the Hold-In-Trust Scheme that is
          administered by Ms Cheo Hock Kuan, Secretary ERCC.

     4.2  You will be given a fixed monthly car maintenance allowance of
          S$2,000. This is to help defray the cost of general maintenance and
          running expenses of your vehicle. It will cover transport expenses
          incurred in the course of official business and you will not be
          eligible to claim for any reimbursement of mileage.

     4.3  You will also receive a fixed monthly driver allowance of S$2,400.

5.   CLUB MEMBERSHIP

     5.1  You will be provided with the American Club Membership.

     5.2  The Company will also reimburse the monthly subscription of the club
          membership.

6.   HOUSE ALLOWANCE

     6.1  You will be provided with a monthly housing allowance of S$15,000.

7.   HOME LEAVE

     7.1  Following every twelve months of service, you will be eligible for
          travel expenses to and from your home country. The travel expenses
          will include air travel fare for yourself and your family members at
          business class round trip direct from Singapore to your home country.
<PAGE>
8.   RELOCATION AND SETTLING IN ALLOWANCES

     8.1  The Company will reimburse you for your relocation expenses up to a
          maximum of S$20,000.

     8.2  You will also receive a settling in allowance of S$25,000.

9.   TAX EQUALIZATION

     9.1  You will pay no more and no less income tax than if you would have
          paid had you remain in US. The Company will absorb any excess tax
          burden arising including any further income tax on the account of tax
          equalization.

10.  DEPENDENTS' EDUCATION

     10.1 The company will reimburse the school fees and transportation fees (up
          to a maximum of 3 children) for executive's whose children attend
          school (from kindergarten through high school).<PAGE>
                                                                    Exhibit 4.16

                             Private & Confidential

24 March 2003

Tan Lay Koon
P&CEO, STATS

Dear Lay Koon

TERMS AND CONDITIONS OF APPOINTMENT

Further to the letter dated 26 June 2002 from Peter Seah to you in respect of
your promotion from Chief Financial Officer to President & Chief Executive
Officer, this is to confirm that the attached terms and conditions are
applicable to your appointment as President & Chief Executive Officer. The
attached embodies all the terms and conditions agreed upon between the Company
and you as to your appointment as P & CEO of the Company and supercedes and
cancels in all respects all the previous agreements, undertakings and
arrangements of any nature if any between the Company and you with respect to
your appointment, whether such be written or oral.

Kindly acknowledge receipt and confirm by signing and returning the duplicate
copy of this letter.

Yours sincerely

/s/ Kuan Kwee Jee
Kuan Kwee Jee
Secretary ERCC
ST Assembly Test Services Ltd
Enc.
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                        ACKNOWLEDGEMENT AND CONFIRMATION

I, Tan Lay Koon, hereby acknowledge receipt and confirm the contents of your
letter herein as correct.

/s/ Tan Lay Koon                                        March 25, 2003
-----------------------------                        -------------------
Signature                                                    Date

<PAGE>
                             Private & Confidential

               TERMS AND CONDITIONS OF APPOINTMENT OF TAN LAY KOON
                  AS PRESIDENT & CHIEF EXECUTIVE OFFICER, STATS
--------------------------------------------------------------------------------

1.   RESPONSIBILITY

     You will be responsible to the Board of Directors for the overall
     profitability and growth of the Company.

2.   REMUNERATION

     a.   Your service grade will be G3. Your monthly salary shall be S$40,000.

     b.   You will also receive the 13th month Annual Wage Supplement (AWS),
          which is pro-rated to your period of service up to and including 31
          December, and is payable if you are in service with the Company on 31
          December.

     c.   Performance and salary review will be conducted annually on or about 1
          July each year. Annual salary increments are based on individual and
          company performances, in accordance with the policies approved by the
          STATS Executive Resource and Compensation Committee (ERCC) from time
          to time.

     d.   Please note that salary and bonus payments are made based on
          individual merits and should therefore be kept strictly confidential.

     e.   Your salary and other special terms will be administered by Secretary
          ERCC.

3.   PERFORMANCE BONUS

     In addition to your base salary, inclusive of the 13th month AWS, you will
     participate in the following incentive plans:

     a.   Performance Target Bonus (PTB): You will be entitled to earn a PTB
          each year, based on the achievement of mutually agreed targets set by
          the Board and yourself. PTB may reach a maximum of 2.5 months of your
          monthly base salary subject to achievement of the performance targets.

     b.   EVA-based Incentive Plan: You will participate in the EVA based
          incentive plan based on sharing as approved by the ERCC.
<PAGE>
                             Private & Confidential

4.   SHARE OPTIONS

     It will be recommended to the ERCC that you be granted an option to
     purchase 2,000,000 ordinary shares under the Employee Share Option Scheme
     (ESOS). The vesting period will be over a period of 4 years and the grant
     price will be determined based on the approved ESOS guidelines. Additional
     grants are planned on an annual basis, based upon individual and company
     performance.

5.   INCENTIVE SHARES

     a.   You will receive 150,000 ordinary shares upon the Company achieving an
          annual revenue of US$500 million with 20% net profit.

     b.   You will receive another 250,000 ordinary shares if the Company
          achieves an annual revenue of US$1,000 million with 25% net profit.

6.   CAR BENEFITS AND EXPENSES

     a.   The company will provide you with a grant of S$200,000 over 6 years
          for purchase of a car under the Hold-in-Trust Scheme subject to the
          terms and conditions of the Car Hold-In-Trust Agreement to be entered
          into by the Company and you.

     b.   You will be given a fixed monthly car maintenance allowance of
          S$2,000. This is to help defray the cost of general maintenance and
          running expenses of your vehicle. It will cover transport expenses
          incurred in the course of official business and you will not be
          eligible to claim for any reimbursement of mileage.

     c.   You will also receive a fixed monthly driver allowance of S$2,400.

7.   CLUB BENEFITS AND EXPENSES

     a.   You will be provided with a grant of S$80,000 over five (5) years for
          the purchase of a club membership under the Hold-in-Trust Scheme.

     b.   You will also be given a monthly club subscription allowance of S$200.

8.   OTHER GENERAL TERMS AND CONDITIONS

     a.   You shall not at any time during your service with the Company either
          directly or indirectly (without prior written consent from the
          Company) engage or interest yourself, whether for reward or
          gratuitously, in any work or business other than relating to your
          duties in the Company.
<PAGE>
                             Private & Confidential

     b.   You shall devote the whole of your time, knowledge, skill and
          attention in the performance of your duties in the Company, and attend
          at the premises where you shall from time to time be posted by the
          Company on such days including, if the exigencies of the work so
          require, on Sunday and public holidays and at such hours as may be
          required.

     c.   You shall enjoy all other standard benefits and be subject to all
          conditions applicable to executives under your job grade.

     d.   The Company reserves the right to vary the terms and conditions of
          service based on business needs from time to time.

     e.   You will abide by the terms and conditions of service, the rates,
          regulations and procedures as may be laid down by the Company from
          time to time and also as contained in the Company's Human Resources
          Manual as revised from time to time.

9.   WORKING HOURS

     a.   Your working hours will be as per company policy.

     b.   As a senior executive staff, you are expected to work beyond normal
          hours based on the exigencies of service without overtime claims.

10.  LEAVE

     You shall be eligible for 21 days of paid leave each year. Your leave
     administration will be as per the company's policy.

11.  EMPLOYEE BENEFITS PROGRAM

     We have put in place a flexible benefits program for our senior employees.
     This program allows for freedom and flexibility to put together the benefit
     package which best suits your needs and that of your immediate family at
     different stages of your career. The flexible benefits brochure together
     with the enrolment instructions will be forwarded to you upon your
     acceptance of the appointment.

12.  CONFIDENTIALITY & SECRECY

     During the continuance of your employment with the Company and at all times
     after the termination of your employment from any cause whatsoever, you
     shall not directly or indirectly disclose, divulge, authorize or permit to
     be disclosed to anyone not properly entitled thereto any trade secrets,
     know-how
<PAGE>
                             Private & Confidential

     and any confidential information relating to the business or financial
     conditions of the Company.

13.  TERMINATION OF SERVICE

     a.   Termination can only be effected in writing by either party, without
          giving any reasons, by giving 3 MONTHS' NOTICE or the payment of a sum
          equivalent to 3 months' salary in lieu of notice.

     b.   All staff benefits shall cease after the last day of service. Any
          money due and owing under any staff loan scheme, scholarships, bonds
          or otherwise payable by you to the Company must be settled before the
          last day of service. The Company reserves the right to offset any
          outstanding sum from the balance of money payable by the Company to
          you.

     c.   Notwithstanding conditions above, the Company reserves the right at
          all times to terminate your services forthwith if you should be guilty
          of misdemeanor, misconduct, negligence or breach of any of the terms
          of this offer or any other existing terms and conditions of service,
          rule or regulation laid down by the Company from time to time for all
          members of its staff.

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