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Exhibit 10.518

CHIRON CORPORATION NOMINATING AND
CORPORATE GOVERNANCE COMMITTEE CHARTER

ROLE

        The Nominating and Corporate Governance Committee (the "Committee") of
the Board of Directors (the "Board") of Chiron Corporation ("Chiron") has two
roles: (1) the Committee determines the slate of director nominees for election
to Chiron's Board and recommends to the Board the individuals to fill vacancies
occurring between annual meetings of stockholders, subject to the requirements
of the Governance Agreement, dated as of November 20, 1994, between Chiron and
Novartis AG ("Novartis"), as amended (as it may be further amended from time to
time, the "Governance Agreement"); and (2) the Committee develops and recommends
to the Board a set of corporate governance principles applicable to Chiron.

MEMBERSHIP AND STRUCTURE

        The Committee shall consist of at least three directors. Subject to that
minimum number, the number of members shall be determined by reference to
Section 2.03(b)(ii) of the Governance Agreement. A member shall not be an
officer or employee of Chiron, each member shall be free of any relationship
that, in the determination of the Board, would interfere with the exercise of
independent judgment in carrying out the responsibilities of a director and each
member shall otherwise be "independent" and qualified to serve as a member of
the Committee under applicable law and under the rules of the Nasdaq Stock
Market, Inc. The Committee shall review at least annually, and upon the
occurrence of any significant change, the qualification and independence of its
members, and shall report the result of this review to the full Board.

        Subject to the requirements described above with respect to Committee
membership, members of the Committee shall be appointed by the Board in
accordance with the Governance Agreement. Committee members shall serve at the
pleasure of the Board. The chairperson shall be appointed by the full Board.

        The Committee shall meet in person or telephonically at least two times
a year, or more frequently when deemed necessary or desirable by the Committee
or its chairperson, at such times and places as the Committee determines.

COMMUNICATIONS/REPORTING

        The Committee shall perform or cause to be performed and approved by the
Committee annually an evaluation of the performance of the Committee of its role
under this charter, including the duties and responsibilities set forth in Annex
A. The evaluation shall include consideration of possible amendments to this
charter, including the duties and responsibilities set forth in Annex A. The
performance evaluation may be conducted in such manner as the Committee deems
appropriate, and the result and recommendations shall be reported to the Board
by the chairperson or any other member of the Committee. The chairperson shall
report in a timely manner on Committee activities to the full Board.

EDUCATION

        Chiron is responsible for providing the Committee with educational
resources relating to its role and duties and responsibilities, including
corporate governance practices, corporate governance rules and requirements,
nominating practices and any other material as may be requested by the
Committee.

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AUTHORITY

        In discharging its roles, duties and responsibilities, the Committee is
empowered to cause and direct the investigation of any matter within its role,
with full power to cause independent counsel or other experts or advisors to be
retained for this purpose. The Committee may require any officer or employee of
Chiron or Chiron's outside lawyers to attend a meeting of the Committee and to
provide any information requested by the Committee or its member or consultants.
The Committee shall have the full authority of the Board to discharge its duties
and responsibilities, including the authority to select, retain, terminate, and
approve the compensation and other terms of engagement of search firms or
consultants, counsel or other experts or advisors, as the Committee deems
appropriate in its discretion, without seeking approval of the Board or
management. The Committee may, in its discretion, delegate all or a portion of
its duties and responsibilities to a subcommittee of the Committee. The
Committee shall also have the resources that it deems necessary to discharge its
duties and responsibilities.

KEY DUTIES AND RESPONSIBILITIES

        The key duties and responsibilities of the Committee in carrying out its
roles are delineated in Annex A to the Nominating and Corporate Governance
Committee Charter. Annex A will be reviewed annually, and updated if necessary,
to reflect changes in regulatory requirements, authoritative guidance and
evolving oversight practices. As the compendium of Committee duties and
responsibilities, Annex A will be considered to be incorporated in, and a part
of, this charter.

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ANNEX A

        The following are the key duties and responsibilities of the Committee:

1.To make recommendations to the Board from time to time as to changes that the
Committee believes to be desirable to the size of the Board or any committee
thereof.

2.To identify individuals believed to be qualified to become Board members and
to determine the nominees to stand for election as directors at the annual
meeting of stockholders or, if applicable, at a special meeting of stockholders.
In nominating candidates the Committee shall take into consideration such
factors as it deems appropriate, subject to the terms of the Governance
Agreement. The Committee may consider candidates proposed by management, but is
not required to do so. In the case of a vacancy in the office of a director
(including a vacancy created by an increase in the size of the Board but other
than a vacancy that Novartis is entitled to fill pursuant to the Governance
Agreement), the Committee shall determine a nominee to such vacancy through
election by the Board.

3.To develop and recommend to the Board standards to be applied in making
determinations as to the absence of relationships between Chiron or its
subsidiaries and a director which, in the opinion of the Board, would interfere
with the exercise of independent judgment in carrying out the responsibilities
of a director ("Director Independence").

4.To assess and make recommendations to the Board on individual Director
Independence in accordance with standards adopted by the Board on a general
basis and with respect to specific issues as and if they arise.

5.In the case of a director nominee to fill a Board vacancy created by an
increase in the size of the Board, make a recommendation to the Board as to the
class of directors in which the individual should serve.

6.Develop and recommend to the Board a set of corporate governance principles
applicable to Chiron, and to review those principles at least once a year.

7.Consider and recommend to the Board procedures for assessing the effectiveness
of corporate governance principles, including evaluation of Board and management
corporate governance processes and performance.

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Exhibit 10.518

CHIRON CORPORATION NOMINATING AND CORPORATE GOVERNANCE COMMITTEE CHARTER
ROLE
MEMBERSHIP AND STRUCTURE
COMMUNICATIONS/REPORTING
EDUCATION
AUTHORITY
KEY DUTIES AND RESPONSIBILITIES

ANNEX A