Exhibit 10.517

CHIRON CORPORATION  SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN

(As Amended and Restated Effective March 1, 2003)

ARTICLE I  PURPOSE

This Plan is designed to restore to selected employees of Chiron Corporation and its affiliates certain benefits that cannot be provided under the Chiron 401(k)
Plan. It shall be effective for compensation earned after December 31, 1997 and to permit additional deferrals of annual bonuses.

This
Plan is intended to be a plan that is unfunded and that is maintained by Chiron Corporation primarily for the purpose of providing deferred compensation for a select group of
management or highly compensated employees within the meaning of the Employee Retirement Income Security Act of 1974 ("ERISA").

ARTICLE II  DEFINITIONS

In this Plan, the following terms have the meanings indicated below:

2.01"Account"means a bookkeeping entry used to record supplemental deferrals and contributions made on a
Participant's behalf under Article III and Article VII of the Plan and any earnings credited to these supplemental deferrals and contributions under Article IV or
Article VII of the Plan. To the extent it considers necessary or appropriate, the Committee or its delegate shall maintain separate a subaccount for each type of supplemental deferral or
contribution under the Plan or shall otherwise provide a means for determining that portion of an account attributable to each type.

2.02"Affiliate"means an entity other than the Company whose employees participate in the 401(k) Plan.

2.03"Beneficiary"means the person or persons, natural or otherwise, entitled to receive a Participant's vested
Account if the Participant dies before distribution of his or her entire vested Account. A Participant's Beneficiary shall, at any time, be the person or persons then designated, whether affirmatively
or by default, as the Participant's beneficiary under the 401(k) Plan. If the Participant no longer has a beneficiary under the 401(k) plan, the Participant may designate one or more primary
Beneficiaries and one or more secondary Beneficiaries for purposes of this Plan. Any such designation will be made in writing pursuant to such procedures as the Committee may establish and delivered
to the Committee before the Participant's death. The Participant may revoke or change this designation at any time before his or her death by following such procedures as the Committee may establish.
If there is no effective Beneficiary designation on file when such a Participant dies, the Participant's vested Account will be distributed to the Participant's spouse if surviving at the
Participant's death, or if there is no such spouse, the Participant's estate.

2.04"Bonus"means the component of an Eligible Employee's Compensation paid in the form of an annual cash
bonus.

2.05"Chiron 401(k) Plan"means the Chiron Corporation 401(k) Plan, as amended from time to time.

2.06"Code"means the Internal Revenue Code of 1986, as amended.

2.07"Committee"means the committee established pursuant to Article XIV of the Chiron 401
(k) Plan, as constituted from time to time. The Committee has full discretionary authority to administer

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and
interpret the Plan, to determine eligibility for Plan benefits, to select employees for Plan participation, and to correct errors. The Committee may delegate its duties and responsibilities and,
unless the Committee expressly provides to the contrary, any such delegation will carry with it the Committee's full discretionary authority to accomplish the delegation. Decisions of the Committee
and its delegate will be final and binding on all persons.

2.08"Company"means Chiron Corporation.

2.09"Compensation"means compensation as established pursuant to Article II of the Chiron 401
(k) Plan, as constituted from time to time.

2.10"Eligible Employee"means an employee of the Company or of an Affiliate at the level of any executive
salary grade position who has been selected by the Committee for Plan participation. An individual will automatically cease to be an Eligible Employee on the earliest of (i) the date the
individual ceases to be an employee of the Company or an Affiliate at the level of an executive salary grade position, (ii) the date specified by the Committee for such cessation or
(iii) the date the Plan is terminated.

2.11"Matching Contribution"means a matching contribution pursuant to Section 5.02 of the Chiron 401(k)
Plan.

2.12"Participant"means a current or former Eligible Employee who retains an Account.

2.13"Plan"means this Chiron Corporation Supplemental Executive Retirement Plan, as amended from time to time.

2.14"Plan Year"means the plan year defined in the Chiron 401 (k) Plan.

2.15"Plan Year Account"means, for each Plan Year, that portion of an Eligible Employee's Account that is
attributable to (i) Compensation that would have been paid in such Plan Year had payment not been deferred under this Plan and (ii) interest credited thereto pursuant to
Article IV.

2.16"Retirement Contribution"means a retirement contribution pursuant to Section 5.03 of the Chiron
401(k) Plan.

2.17"Salary Deferral"means a salary deferral pursuant to Section 5.01 of the Chiron 401(k) Plan.

2.18"Special Deferred Compensation Arrangement"means any written deferred compensation arrangement entered
into between and signed by an Eligible Employee and the Company, or an Affiliate thereof, which is approved by the Committee or its delegate pursuant to Section 7.01 hereof.

2.19"Termination of Employment"means termination of employment with the Company and all Affiliates, other than
by reason of death.

ARTICLE III  DEFERRALS AND CONTRIBUTIONS

3.01Supplemental Salary Deferrals.



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3.02Supplemental Matching Contributions.



3.03Supplemental Retirement Contributions.



ARTICLE IV  EARNINGS

Interest will be credited to each Account at the end of each calendar quarter, in accordance with procedures approved by the Committee. The interest rate used
will be based on the Moody's Corporate Bond Yield Average. The Corporate Bond Yield Average is equal to the average of the Moody's Corporate AAA, AA, A and BAA Bond Yield Averages, determined as of
the first business day of that quarter. The first quarter for which interest will be credited is the calendar quarter beginning January 1, 1998.

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ARTICLE V  VESTING

Participants will be 100% vested in that portion of their Accounts attributable to supplemental salary deferrals and supplemental matching contributions and will
vest in that portion of their Accounts
attributable to supplemental retirement contributions in the same manner that they vest in Retirement Contributions. That portion of a Participant's Account attributable to amounts deferred under a
Special Deferred Compensation Arrangement shall vest in accordance with the terms of that arrangement.

ARTICLE VI  DISTRIBUTIONS

6.01Standard Distribution Options





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6.02Death.Subject to Article VII (relating to certain distributions of Special Deferred Compensation
Arrangements), if a Participant dies with a vested amount in his or her Account, whether or not the Participant was receiving payouts from that Account at the time of his or her death, the
Participant's Beneficiary will receive the entire vested amount in the Participant's Account within the 30 day period beginning 30 days after (and ending 60 days after) the
Committee learns of the Participant's death and has verified the Beneficiary's right to payment.

6.03Accelerated Distributions.Pursuant to the following restrictions, a Participant may accelerate the time
and form of distribution:



6.04Withholding.The Company will deduct from Plan payouts, or from other compensation payable to a Participant
or Beneficiary, amounts required by law to be withheld for taxes with respect to benefits under this Plan. The Company reserves the right to reduce any supplemental deferral or contribution that would
otherwise be made under this Plan on behalf of a Participant to satisfy the Participant's tax withholding liabilities.

ARTICLE VII  SPECIAL DEFERRED COMPENSATION ARRANGEMENTS

7.01General.If an Eligible Employee enters into a separate written arrangement with the Company or an
Affiliate, signed by both parties, for the payment of nonqualified deferred compensation or the Company authorizes the deferral of additional types of compensation arrangements (including but not
limited to severance payments, special bonuses, bonuses or other compensation earned with a predecessor company, etc.) pursuant to a separate written arrangement signed by the Eligible Employee and
the Company or an Affiliate (each a "Special Deferred Compensation Arrangement"), payment of such compensation shall be made through this Plan, unless expressly specified otherwise under such
arrangement.

7.02Defined Contribution Arrangements.If the Special Deferred Compensation Arrangement is in the nature of a
defined contribution arrangement, the deferred amount will be credited to the Eligible Employee's Account when such amounts would otherwise have been paid or when specified under the arrangement.
Amounts so credited to the Eligible Employee's Account will be credited with

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earnings
and, to the extent vested under the arrangement, shall become distributed in accordance with the terms of the Plan, except to the extent specified under the arrangement.

7.03Defined Benefit Arrangements.If a Special Deferred Compensation Arrangement is in the nature of a defined
benefit arrangement, the benefit shall be payable hereunder, at the time and in the form specified in the arrangement.

ARTICLE VIII  PRIOR CCD PLAN

This Plan shall supersede and replace the Ciba Corning Diagnostics Corp. Supplemental Executive Retirement Plan (the "CCD SERP") effective January 1, 1998,
other than with respect to Supplemental Pension Plan Benefits thereunder. As a result, no further Supplemental Investment Plan Credits shall be made under the CCD SERP with respect to compensation
earned after December 31, 1997 and all Supplemental Investment Plan Credits (including earnings thereon as of December 31, 1997) attributable to compensation earned by a Participant
before January 1, 1998 shall be credited to such Participant's Account under this Plan effective January 1, 1998 and shall be subject thereafter to this Plan's provisions, including but
not limited to this Plan's provisions relating to earnings (for periods after December 31, 1997) and distribution. However, that portion of an Account attributable to Supplemental Investment
Plan Credits under the CCD SERF (including earnings thereon) shall vest in the same manner that the underlying qualified plan contributions (i.e. that they supplemented) vest under the 401(k) Plan. If
such an individual would not otherwise be a Participant in this Plan effective January 1, 1998, he or she must elect no later than December 31, 1997, in accordance with such procedures
as the Committee shall specify, the manner in which his or her vested Account will be paid out in accordance with Article V of this Plan.

ARTICLE IX  MISCELLANEOUS

9.01Limitation of Rights.Participation in this Plan does not give any individual the right to be retained in
the service of the Company or of any related entity.

9.02Satisfaction of Claims.Payments to a Participant, the Participant's legal representative, or Beneficiary
in accordance with the terms of this Plan will, to the extent thereof, be in full satisfaction of all claims that person may have hereunder against the Committee, the Company, and all Affiliates, any
of which may require, as a condition to payment, that the recipient execute a receipt and release in a form determined by the Committee, the Company, or an Affiliate.

9.03Indemnification.The Company and the Affiliates will indemnify and hold harmless the Directors, the members
of the Committee, and employees of the Company and the Affiliates who may be deemed fiduciaries of the Plan, from and against any and all liabilities, claims, costs and expenses, including attorneys'
fees, arising out of an alleged breach in the performance of their fiduciary duties under the Plan, other than such liabilities, claims, costs and expenses as may result from the gross negligence or
willful misconduct of such persons. The Company and the Affiliates shall have the right, but not the obligation, to conduct the defense of such persons in any proceeding to which this Section applies.

9.04Assignment.To the fullest extent permitted by law, benefits under the Plan and rights thereto are not
subject in any manner to anticipation, alienation, sale, transfer, assignment, pledge, encumbrance, attachment, or garnishment by creditors of a Participant or a Beneficiary.

9.05Inability to Locate Recipient.If a benefit under the Plan remains unpaid for two years from the date it
becomes payable solely by reason of the inability of the Committee to locate the Participant or Beneficiary entitled to the payment, the benefit shall be treated as forfeited. Any amount forfeited

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in
this manner shall be restored without interest upon presentation of an authenticated written claim by the person entitled to the benefit.

9.06Amendment and Termination.The Company's Board of Directors may, at any time, amend or terminate the Plan.
In addition, the Committee may amend the Plan (other than this Section 9.06), provided that no such amendment may cause any substantial increase in cost to the Company or to any Affiliate. Any
amendment must be made in writing; no oral amendment will be effective. No amendment may, without the consent of an affected Participant (or, if the Participant is deceased, the Participant's
Beneficiary), adversely affect the Participant's or the Beneficiary's rights and obligations under the Plan with respect to amounts already credited to a Participant's Account. Notwithstanding the
foregoing, if the Plan is terminated, the Company's Board of Directors may determine that all Accounts will be paid out as soon as practicable thereafter in single sum payments.

9.07Applicable Law.To the extent not governed by Federal law, the Plan is governed by the laws of the State of
California. If any provision of the Plan is held to be invalid or unenforceable, the remaining provisions of the Plan will continue to be fully effective.

9.08No Funding.The Plan constitutes a mere promise by the Company and the Affiliates to make payments in the
future in accordance with the terms of the Plan. Except to the extent provided below in Section 9.09, Participants and Beneficiaries have the status of general unsecured creditors of the
Company and the Affiliates and Plan benefits will be paid from the general assets of the Company and the Affiliates and nothing in the Plan will be construed to give any Participant or any other
person rights to any specific assets of the Company or the Affiliates. In all events, it is the intention of the Company, all Affiliates and all Participants that the Plan be treated as unfunded for
tax purposes and for purposes of Title I of ERISA.

9.09Salary Deferral Trust.Plan benefits attributable to the supplemental salary deferrals of Participants
shall be paid from the assets of a grantor trust (the "Trust") established by the Company to assist it in meeting its obligations and, to the extent that such assets are not sufficient, by the
Company. The Trust
shall conform to the terms of the Internal Revenue Service Model Trust as described in Internal Revenue Service Revenue Procedure 92-64.

IN
WITNESS WHEREOF, Chiron Corporation has caused this Plan, as amended and restated effective March 1, 2003 to be executed by its duly authorized representative on the date
indicated below.

|                             |  |                   
|---------------------------- |  | ------------------
|/s/WILLIAM G. GREENSignature |  | March 14, 2003Date

|Name:  |  | William G. Green                                |  | 
|------ |  | ----------------------------------------------- |  | 
|Title: |  | Sr. Vice President,
General Counsel & Secretary |  | 

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