<PAGE>
                                                                    Exhibit 4.50



                                                                ALLEN & GLEDHILL
                                                          ADVOCATES & SOLICITORS



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                             Dated 31 December 2004

                         SINGAPORE TECHNOLOGIES PTE LTD


                                       and


                           TERRA INVESTMENTS PTE. LTD.


                                       and


                       CHARTERED SILICON PARTNERS PTE LTD

                               NOVATION AGREEMENT





                                                 ALLEN & GLEDHILL
                                                 ONE MARINA BOULEVARD #28-00
                                                 SINGAPORE 018989

<PAGE>
                                                           Private Lot A12787(d)



                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
CONTENTS                                                              PAGE
<S>     <C>                                                           <C>
1.      INTERPRETATION...............................................   1

2.      SECURITY DEPOSIT.............................................   2

3.      NEW LANDLORD'S UNDERTAKINGS..................................   2

4.      TENANT'S UNDERTAKINGS........................................   3

5.      COSTS AND EXPENSES...........................................   3

6.      CONTRACTS (RIGHTS OF THIRD PARTIES) ACT......................   3

7.      GOVERNING LAW................................................   3
</TABLE>





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                                       i
<PAGE>
                                                           Private Lot A12787(d)



THIS AGREEMENT is made on 31 December 2004 BETWEEN:

(1)  SINGAPORE TECHNOLOGIES PTE LTD, a company incorporated in Singapore and
     having its registered office at 51 Cuppage Road #09-01 StarHub Centre
     Singapore 229469 (the "ORIGINAL LANDLORD");

(2)  TERRA INVESTMENTS PTE. LTD. a company incorporated in Singapore and having
     its registered office at 60B Orchard Road #06-18 Tower 2 The Atrium @
     Orchard Singapore 238891 (the "NEW LANDLORD"); and

(3)  CHARTERED SILICON PARTNERS PTE LTD, a company incorporated in Singapore and
     having its registered office 60 Woodlands Industrial Park D Street 2
     Singapore 738406 (the "TENANT").


WHEREAS:

(A)  By the Lease (as defined below), the Original Landlord leased to the Tenant
     the Premises (as defined below) for the Term (as defined below), subject to
     the compliance by the Tenant of the tenant's obligations and the conditions
     contained in the Lease.

(B)  By an Agreement (as defined below) made between the Original Landlord and
     the New Landlord, the Original Landlord agreed to sell / transfer to the
     New Landlord the Premises together with the benefit of and subject to the
     Lease.

(C)  The Original Landlord wishes to be released and discharged from further
     performance of the Lease and the Tenant has agreed to release and discharge
     the Original Landlord subject to the New Landlord's agreement to perform
     the Lease and to be bound by the terms of the Lease in place of the
     Original Landlord on the terms and conditions set out below.

IT IS AGREED as follows:


1.   INTERPRETATION

1.1  Definitions

     The following definitions apply unless the context requires otherwise:

     1.1.1 "AGREEMENT" means collectively the (1) a Sale and Purchase Agreement
           dated 15 December 2004 made between the Original Landlord and the New
           Landlord and (2) a letter of nomination dated 31 December 2004 issued
           by Temasek Holdings (Private) Limited, a company incorporated in the
           Republic of Singapore and having its registered office at 60B Orchard
           Road #06-18 Tower 2, The Atrium @ Orchard Singapore 238891 pursuant
           to the terms of the Sale and Purchase Agreement, nominating the New
           Landlord;

     1.1.2 "EFFECTIVE DATE" means 1 January 2005;

     1.1.3 "LEASE" means the agreement for sub-licence and sub-lease dated 24
           September 1999 made between the Original Landlord and the Tenant in
           respect of the Premises;

     1.1.4 "PERSON" means a person, firm, company or corporation;

                                     - 1 -
<PAGE>
                                                           Private Lot A12787(d)



     1.1.5 "PREMISES" means all that piece of land known as Private Lot
           A12787(d) (part of Government Survey Lots 230L and 1179P) of Mukim 13
           as shown on the plan attached to the Building Agreement dated 24
           September 1999 made between Jurong Town Corporation and the Original
           Landlord; and

     1.1.6 "TERM" means 30 years (less 1 day) commencing on 1 July 1997.

1.2  General

     Headings are for convenience only and do not affect interpretation. The
     following rules of interpretation apply unless the context requires
     otherwise:

     1.2.1 the singular includes plural and conversely;

     1.2.2 a gender includes all genders;

     1.2.3 a reference to any party to this Agreement or any other agreement or
           document includes the party's successors or assigns;

     1.2.4 a reference to a right or obligation of any two or more persons
           confers that right, or imposes that obligation, on each of them
           individually and both (or all) of them together; and

     1.2.5 unless stated otherwise, one word or provision does not limit the
           effect of another.


2.   SECURITY DEPOSIT

     Each of the Original Landlord, the New Landlord and the Tenant hereby
     confirms and acknowledges that notwithstanding any agreement to the
     contrary, no rental deposit had been paid by the Tenant to the Original
     Landlord in respect of the lease by the Tenant to the Original Landlord nor
     has the Original Landlord received any rental deposits in respect of the
     lease of the Premises.


3.   NEW LANDLORD'S UNDERTAKINGS

3.1  With effect from the Effective Date, the New Landlord hereby undertakes
     with:

     3.1.1 the Original Landlord to perform the Lease and to be bound by all the
           terms, obligations, stipulations and conditions thereof in every way
           as if the New Landlord were originally named as a party to the Lease
           in lieu of the Original Landlord; and

     3.1.2 the Tenant to perform the Lease and to be bound by all the terms,
           obligations, stipulations and conditions thereof in every way as if
           the New Landlord were originally named as a party to the Lease in
           lieu of the Original Landlord,

     and the New Landlord will accordingly duly and punctually perform and
     observe all the terms, obligations, stipulations and conditions of the
     Lease on the part of the Original Landlord to be performed and observed.
     The New Landlord shall keep the Original Landlord fully indemnified against
     all claims, demands, actions, proceedings, damages, losses, costs, expenses
     and liabilities caused or contributed by any default or failure on the New
     Landlord's part to discharge and fulfil as aforesaid the Original
     Landlord's

                                     - 2 -

<PAGE>
                                                           Private Lot A12787(d)



     obligations under the Lease, to the intent that the Original Landlord shall
     be under no further obligations or liabilities to and suffer no loss or
     expense under any claim made by the Tenant in respect of the Lease.

3.2  Nothing in this Agreement shall affect the obligations and liabilities of
     the Original Landlord under the Lease which have arisen or accrued at any
     time prior to the Effective Date and all such obligations and liabilities
     which have arisen or accrued at any time prior to the Effective Date and
     the terms and conditions of the Lease applicable in relation thereto shall
     continue in full force and effect and be binding on the Original Landlord.

3.3  Nothing in this Agreement shall impose on the New Landlord any obligations
     or liabilities under the Lease which may have arisen and accrued at any
     time prior to the Effective Date.


4.   TENANT'S UNDERTAKINGS

4.1  The Tenant hereby releases and discharges the Original Landlord from the
     further performance of the Lease with effect from the Effective Date and
     from all obligations, claims, demands and liabilities whatsoever under the
     Lease arising on or after the Effective Date and the Tenant hereby accepts
     the obligations and liability of the New Landlord in lieu of the Original
     Landlord in respect of all such obligations, claims, demands and
     liabilities whatsoever under the Lease arising on or after the Effective
     Date and hereby undertakes with the New Landlord that it shall be bound by
     all the terms, obligations, stipulations and conditions of the Lease in
     every way as if the New Landlord were originally named as a party to the
     Lease in lieu of the Original Landlord.


5.   COSTS AND EXPENSES

5.1  Each party shall bear its own legal and other costs and expenses (including
     any goods and services tax thereon) in the preparation and completion of
     this Agreement.

5.2  The New Landlord shall bear the stamp duty payable on this Agreement (in
     triplicate).


6.   CONTRACTS (RIGHTS OF THIRD PARTIES) ACT

     A person who is not a party to this Agreement has no right under the
     Contracts (Rights of Third Parties) Act, Chapter 53B of Singapore to
     enforce or enjoy the benefit of any term of this Agreement.


7.   GOVERNING LAW

     This Agreement shall be governed by the laws of Singapore.

                                     - 3 -
<PAGE>
                                                           Private Lot A12787(d)



IN WITNESS WHEREOF the parties hereto have entered into this Agreement on the
day and year first abovewritten.



<TABLE>
<S>                                         <C>   <C>
SIGNED by Chia Yue Joo                      )
                                            )
for and behalf of                           )
                                            )
SINGAPORE TECHNOLOGIES PTE LTD              )     /s/ Chia Yue Joo
                                            )
in the presence of:                         )
                                            )
/s/ Lim Tchuang Cheio
---------------------

Witness's signature
Name: Lim Tchuang Cheio
Address:
Occupation: Manager, Legal




SIGNED by Yap Chwee Mein                    )
                                            )
for and behalf of                           )
                                            )
TERRA INVESTMENTS PTE. LTD.                 )     /s/ Yap Chwee Mein
                                            )
in the presence of:                         )
                                            )
/s/ Chng Yin Hun
----------------

Witness's signature
Name: Chng Yin Hun
Address:
Occupation: Associate Director, Finance




SIGNED by Chia Song Hwee                    )
                                            )
for and behalf of                           )
                                            )
CHARTERED SILICON PARTNERS PTE LTD          )     /s/ Chia Song Hwee
                                            )
in the presence of:                         )
                                            )
/s/ Chow Min Wei
----------------

Witness's signature
Name: Chow Min Wei
Address:
Occupation: Legal Counsel
</TABLE>

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