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C H I R O N




May 6, 1996                                                       CONFIDENTIAL
                                                                  ------------

Magnus Lundberg
Gullvivivevagen #5
75655 Uppsala, Sweden

Dear Magnus:

We are pleased to confirm our offer of employment as Vice President, Chiron 
Corporation, reporting to me.  Your starting salary will be paid at a monthly 
rate of $14,583 ($175,000 annually) as an exempt employee.  The details of 
your Employment Contract will be outlined at a later date.

You will be eligible to participate in our Stock Option Program. Subject to 
the approval of the Board of Directors, you will be awarded a stock option 
grant of 7,500 shares.  We expect that the grant will be approved and 
effective within 90 days of your employment date.  The exercise price of the 
option will be set at the actual market price of a share of stock on the date 
the grant is approved.  Under the option program as it is currently 
administered, you will be eligible for additional annual stock option grants 
based on your performance.

You will be eligible to participate in Chiron's Executive Variable 
Compensation Plan, which as structured, is paid out in the first quarter of 
each calendar year based upon company and individual performance in the 
preceding year.  Your first payout will be made in the first quarter of 1997. 
The payout potential for your position under the current program will be a 
maximum of 60% of your annual salary.  You will be guaranteed a minimum of 
30% for the first two years of employment.  Additionally, you will be 
provided a company car of a value up to $33,000 for your use during your stay 
in the Bay Area.

The following are highlights of your Chiron benefits.  Some are effective 
immediately upon your employment, while there are established enrollment 
periods for others.  Your group medical insurance benefits start on the first 
day of the month following your date of hire.

     1.  A choice of medical and dental coverage for you and your eligible
         dependents.

     2.  Three weeks paid vacation per year.


CHIRON CORPORATION - 4560 Horton Street - Emeryville, CA - 94608-2916 - 
510-655-8730

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Magnus Lundberg
May 6,1996
Page 2

     3.  Eight scheduled and two floating paid holidays per year.

     4.  Eligible employees (20 hours or more per week) accrue 10 days of
         sick leave per calendar year.

     5.  401(k) tax-deferred investment plan.

     6.  Employee stock purchase plan.

     7.  Tuition reimbursement program.

     8.  Disability salary continuation plan.

     9.  Life and accidental death/dismemberment insurance.

A member of the Human Resources Department staff will assist you with all 
aspects of your temporary relocation to the San Francisco Bay Area.  Chiron 
provides a relocation package for you which will cover the following items:

     *   One house-hunting trip to the San Francisco Bay Area for you and
         your family. Travel arrangements and tickets must be secured through 
         the Chiron Travel Department.

     *   Relocation counseling assistance.

     *   Movement of your household goods to the San Francisco Bay Area.

     *   Storage of household goods for up to 120 days.

     *   A housing allowance for your stay in the San Francisco Bay Area.

     *   Travel to the San Francisco Bay Area for you and your family so
         that you may start work on a date that is yet to be determined. 
         Travel arrangements and tickets must be secured through the Chiron
         Travel Department.

As part of Chiron's medical surveillance program, you will be required to 
provide a baseline blood draw.

This offer is contingent upon your ability as required by federal law, to 
establish your employment eligibility as a U.S. citizen, a U.S. lawful 
permanent resident, or an individual specifically authorized for employment 
in the U.S. by the Immigration and Naturalization Service.  Please read the 
enclosed notice specifying the documentation required in this

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Magnus Lundberg
May 6, 1996
Page 3

regard.  If you have an employment authorization document (EAD) issued by the 
Immigration & Naturalization Service, please contact Rick Ross at 
(510) 601-2511. This allows us to ensure that your authorized employment will 
not lapse during your period of employment with Chiron.  If possible, we request
that you present your Social Security card to Human Resources for the purpose 
of verifying that your payroll records are accurately recorded.

Magnus, we hope the terms of this offer are satisfactory and we look forward to
a favorable response.  If you have questions in the meantime, feel free to 
call me.

Sincerely,

CHIRON CORPORATION


/s/ Edward E. Penhoet

Edward E. Penhoet, Ph.D.
President and Chief Executive Officer

Enclosure

cc:  Human Resources

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May 25, 1996



Magnus Lundberg
Gullvivivevagen #5
75655 Uppsala, Sweden


Dear Magnus:

      This letter confirms the exchange of correspondance and conversations 
we've had regarding the terms of your employment.

      We reaffirm our commitment to pay reasonable costs for moving you and 
your immediate family, along with your household goods, to the San Francisco 
Bay Area at a specific date this fall. Further, Chiron will absorb all 
reasonable costs associated with moving your family and household goods back 
to Sweden approximately one year later.

      Your offer of employment is contingent upon your ability to establish 
employment eligibility in the United States. In that regard, Chiron's Legal 
and Human Resources departments will be at your disposal in handling these 
matters.

      I confirm that you will receive four weeks' vacation per calendar year.

      With respect to notice of termination, either you or Chiron can give 
notice of termination. Said termination would take place six months from the 
written notification. Your employment and salary would continue up to that 
termination date. You would be entitled to severance pay equivalent to one 
year's salary and benefits, including the six month notice period.

      We will provide you with financial assistance in the renting of a home 
in the San Francisco area in the form of a monthly contribution not to exceed 
$2,000.


Sincerely,


Edward E. Penhoet
President and Chief Executive Officer