Exhibit 10.A
                                  COVANCE INC.
                           VARIABLE COMPENSATION PLAN
                            Effective January 1, 2001


1.       Purpose: The purpose of the Covance Inc. Variable Compensation Plan (as
         amended, modified or supplemented, from time to time, the "Plan") is to
         reward the accomplishments of participating employees of Covance Inc.
         ("Covance") and its subsidiaries (collectively, the "Company") in
         achievement of company performance versus targets. The Plan does not
         constitute an amendment, supplement or modification of any individual
         employment agreement between the Company and an employee.

2.       Eligibility: Variable compensation awards under the Plan may be made to
         individuals who are full-time or part-time employees of the Company
         (including executives of the Company) provided that:

         (a)  The employee is employed with the Company on or before October 1
              of the performance year in question; provided, however, that in
              the event an individual commences employment with the Company
              after October 1 of the performance year in question but otherwise
              satisfies the eligibility or performance requirements of the
              Plan, then a variable compensation award may be made upon the
              chief executive officer's ("CEO") recommendation. If the employee
              commences employment with the Company after January 1 of the
              performance year in question but before October 1 of such year and
              otherwise satisfies the eligibility or performance requirements of
              the Plan, then such employee's variable compensation award, if
              any, shall be prorated based on the actual service provided by the
              employee for the performance year in question based either on time
              worked or base pay earned.

         (b)  In the case of Individual Contributor employees (as defined in
              Appendix 2), the employee is employed by the Company on December
              15 of the performance year and, in the case of other employees,
              the employee is employed by the Company both on December 31 of
              the performance year and on the payment date (usually mid-March
              of the following calendar year), provided, however, that (i) in
              the event an employee leaves the Company as a result of death or
              disability the employee shall be eligible for an award which
              shall be prorated based on actual service provided by the
              employee for the performance year in question based on time
              worked or base pay earned in the performance year in question; and
              (ii) in the event a Manager/Supervisor or Key Executive employee's
              employment is terminated by the Company due to a reduction in
              force between December 31 and the payment date, the employee shall
              be eligible for an award.

         (c)  With respect to Individual Contributor employees, the employee is
              in good standing, not on probation or involved in a formal work
              improvement program on the payment date; and

         (d)  The employee is not eligible to participate in any other Company
              variable compensation plan, sales compensation plan or other
              similar plan.
<PAGE>

3.       Administration/Disputes: The Compensation and Organization Committee of
         the Covance Board of Directors (the "Committee"), consisting of at
         least two members who qualify as outside directors under applicable
         Internal Revenue Code and Securities and Exchange Commission (the
         "SEC") rules, codes and regulations, shall manage and administer the
         Plan. No member of the Committee shall be eligible for awards under the
         Plan. The Committee may adopt such policies, rules and regulations that
         it deems necessary for governing, managing or administering the Plan.
         To the extent consistent with the Company's Amended and Restated
         Certificate of Incorporation, no member of the Committee shall be
         liable for any action or determination with respect to the Plan, and
         the members shall be entitled to indemnification and reimbursement in
         the manner provided in the Company's Amended and Restated Certificate
         of Incorporation, as amended, modified or supplemented from time to
         time. In the performance of its functions under the Plan, the Committee
         shall be entitled to rely upon information and advice furnished by the
         Company's officers, accountants, counsel and any party the Committee
         deems necessary, and no member of the Committee shall be liable for any
         action taken or not taken in reliance upon any such advice. Any dispute
         or disagreement which shall arise under, or as a result of, or pursuant
         to, this Plan shall be finally determined by the Committee in its
         absolute and uncontrolled discretion, and any such determination or any
         other determination by the Committee under or pursuant to this Plan and
         any interpretation by the Committee of the terms of this Plan, shall be
         final, binding and conclusive on all persons affected thereby.

4.       Performance Year: The plan year is from January 1 through December 31.

5.       Performance Targets:

         (a)  Business Units. The CEO shall propose for the approval of the
              Committee the performance targets for each Business Unit of the
              Company, including Covance Corporate (see Appendix 1 for a list of
              units for the 2001 performance year). The performance targets
              shall be based on pre-bonus operating margin, or such other
              financial targets as the Committee shall determine. Corporate HR
              and Finance shall maintain a copy of the objectives.

         (b)  Individual Objectives. The Committee shall approve the objectives
              for the performance year of the CEO and the CEO shall approve the
              objectives of his direct reports, including the Corporate Senior
              Vice Presidents. In the case of the CEO and his executive
              management team, including the Corporate Officers, such
              objectives shall be based on a variety of performance measures,
              such as operating margin, and measures of customer satisfaction
              and operational and people excellence.

         (c)  Percentage Payout. The Committee shall establish performance pool
              percentage payouts setting the percentage payout level, including
              the lowest and highest percentage payout that the pool will pay
              out for actual business unit results against target for each
              category of employee participating in the Plan.

         (d)  Bonus Target Percentages. The Committee shall review bonus target
              percentages for each category of participating employee. The
              target is reflected as a percentage of an employee's base pay
              earned during the performance year in question (the "Employee
              Bonus Percentage"). The product of an employee's base pay earned
              during the performance year and the applicable Employee Bonus
              Percentage is the "Employee Bonus Target Amount").

                                       2
<PAGE>

         (e)  Performance Assessment Categories. The CEO shall establish, and
              the Committee shall review, performance assessment categories and
              the impact of such performance assessment on such individuals'
              variable compensation award, if any, under the Plan.

6.       Determination of Business Unit Bonus Pools and Total Bonus Pool: The
         Committee shall certify the Business Units' financial results and
         approve the amount of the total Bonus Pool before the payment of any
         variable compensation under the Plan; provided, however, that for the
         purpose of determining the awards to Individual Contributor employees,
         the CEO shall estimate the Business Unit financial results based on
         performance through November 30 of the performance year in question.
         Payout shall be made to such employees on the basis of such estimates.
         The total Bonus Pool shall be the aggregate of the bonus pools for all
         of the Business Units determined in accordance with Section 5. The
         Committee shall also determine whether the objectives of the CEO have
         been satisfied for the performance year in question. The CEO shall
         assess the performance of his executive management, including the
         Corporate Senior Vice Presidents, compared to their applicable
         objectives for the performance year in question and shall, at the
         Committee's request, review such assessments with the Committee.

7.       Bonus Pool Allocations:

         (a)  Individual Contributor Awards. The variable compensation award for
              Individual Contributor employees shall be determined by
              considering the employee's Business Unit's performance compared to
              its Financial Target, the bonus payout percentage represented by
              such results (the "Business Unit Target Percentage"), and the
              employee's Employee Bonus Percentage.

         (b)  Managers/Supervisors and Key Executive Management. The variable
              compensation award for Manager/Supervisor employees and Key
              Executive/Executive Management employees shall be determined by
              considering the employee's Business Unit Target Percentage, the
              employee's Employee Bonus Percentage and individual performance
              assessment; provided, however, that with respect to employees who
              are not Corporate Vice Presidents of the Company or higher, the
              CEO shall have the authority to adjust, after consultation with
              appropriate members of management, any individual's variable
              compensation award under the Plan; provided, further, however,
              that in no event shall the aggregate amount of the variable
              compensation payments to a Business Unit for a performance year
              exceed such Business Unit's bonus pool.

         (c)  General Manager Discretionary Awards. Each Business Unit General
              Manager and, in the case of Covance Corporate, the CEO, shall have
              the discretion and authority to allocate an additional amount
              equal to up to 5% of the Business Unit bonus pool or such greater
              amount as the Committee shall authorize in any performance year
              (the "Discretionary Bonus") to any plan participant(s) who is not
              a Corporate Vice President or higher based on his/her sole and
              absolute judgment that such individual or entity has made a
              significant contribution to the Company's success or for some
              other important business reason. Such Discretionary Bonus shall
              not be paid until all other amounts payable under the Plan have
              been paid.

                                       3
<PAGE>

         (d)  Special Incentive Pool. In the event a Business Unit exceeds its
              performance target, a special incentive pool shall be established
              from which additional incentive awards shall be made to Key
              Executives/Executive Management, provided, however, that members
              of the Global Leadership Council (which shall include the CEO and
              all Corporate Senior Vice Presidents) and recipients of
              performance shares under the Employee Equity Participation Plan
              during the performance year in question shall not be eligible for
              awards from the Special Incentive Pool.

8.       Adjustments:

         (a)  Discretionary Adjustments. The CEO or the Committee, as
              applicable, may in calculating the amount of the total Bonus Pool
              and Bonus Pool for each Business Unit as of the end of the
              performance year in question and assessing whether the financial
              targets and objectives, in each case, have been satisfied, in
              whole or in part, as applicable, or exceeded on a basis consistent
              with circumstances existing when such financial targets and
              objectives, in each case, were established include or exclude, as
              applicable, the effect on the financial targets and objectives
              arising from any acquisition of the stock or assets of any other
              person or entity, the divestiture of all or any of the Company's
              businesses, restructurings, strategic expenditures by Covance
              identified to the Covance Board of Directors as such, force
              majeure events, material litigation, or any other unexpected or
              unforeseen extraordinary event or occurrence during the
              performance year.

         (b)  Prorations. In furtherance of the second proviso of Paragraph
              7(a), the computation of any individual variable compensation
              award to any employee under this Plan (including the CEO and
              executive management) shall be prorated for the aggregate effect
              of individual performance assessments that, without giving effect
              to such proration, would result in variable compensation awards
              that would otherwise exceed the amount of the Bonus Pool for any
              Business Unit for the performance year in question.

9.       Payment Dates: Awards shall be paid no later than December 15 of the
         applicable performance year for the Individual Contributor employees
         and no later than March 15 following the close of the applicable
         performance year for the Manager/Supervisors and Key
         Executive/Executive Management employees. Awards are subject to all
         applicable tax laws and withholding requirements.

10.      Earned Base Pay: For purposes of the Plan, earned base pay is defined
         as the cumulative base salary paid to an employee during the Plan year.
         Because Individual Contributor awards shall be paid out before the end
         of the Plan year (mid-December of the Plan year), earned base pay will
         be defined as cumulative base salary paid up to Mid-November plus an
         estimated amount of earned base pay for the remainder of the Plan year,
         using the formula stated below:

         (Cumulative Earned Salary) + (Per Pay Period Salary times the # of Pay
         Periods Remaining in Plan Year)

11.      Governing Law; Binding Effect: THIS PLAN SHALL BE GOVERNED BY AND
         CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW JERSEY
         (WITHOUT REGARD TO THE CONFLICT OF LAW PROVISIONS THEREOF) AND ALL
         QUESTIONS CONCERNING THE VALIDITY AND CONSTRUCTION THEREOF SHALL BE
         GOVERNED IN ACCORDANCE WITH THE LAWS OF SAID STATE; PROVIDED, HOWEVER,
         THAT ALL MATTERS OF CORPORATE GOVERNANCE AND OTHER CORPORATE MATTERS
         CONCERNING DELAWARE CORPORATION SHALL BE GOVERNED BY THE DELAWARE
         GENERAL CORPORATION LAW.

                                       4
<PAGE>

         Except as otherwise expressly provided herein, this Plan shall be
         binding upon and inure to the benefit of the parties hereto, their
         legal representatives, successors and assigns.

12.      Termination of Employment: Participation in the Plan does not create a
         contract of employment, or grant any employee of the Company the right
         to be retained in the service of, or otherwise employed by, the
         Company. Individuals will not receive a variable compensation award
         under this Plan for the performance year in which their employment
         terminates for any reason or no reason or if they are terminated for
         any reason or no reason prior to the date the variable compensation is
         actually paid for the performance year in question, except where
         otherwise provided in Paragraph 2 hereof. Without limiting the
         foregoing or Paragraph 2 hereof, any individual whose employment is
         terminated for wrongdoing, including, but not limited to, a violation
         of the Company's Business Integrity Plan, including the code of
         conduct, will forfeit all rights to payment under this Plan.

13.      Amendment, Suspension, or Termination: The Board or Committee may, at
         any time, suspend, terminate, waive or amend the Plan (or provisions
         hereof, as applicable), in such respects as the Board or Committee
         deems to be in the best interest of the Company. No amendment will
         adversely affect any right of any grantee, or his successors in
         interest, to keep any variable compensation award actually made
         hereunder before the effective date of the amendment. Plan deferrals,
         if any, in effect at the Plan's termination remain in effect according
         to their original terms.

14.      Effective Date: The Plan will take effect as of January 1, 2001 and
         supersedes in its entirety the Covance Inc. Variable Compensation Plan
         approved on February 24, 2000 (and effective January 1, 2000), the
         Covance Inc. Variable Compensation Plan approved on February 25, 1999
         (and effective January 1, 1999), the Covance Way Covance Inc. Variable
         Compensation Plan, as amended, effective January 1, 1998, the Covance
         Inc. Variable Compensation Plan, as amended, and effective January 1,
         1997, the Covance Inc. General Employee Variable Compensation Plan, as
         amended, and effective January 1, 1997 and the Covance Biotechnology
         Services Inc. Variable Compensation Plan, as amended, and effective
         January 1, 1997.

                                       5
<PAGE>

                                                                      Appendix 1

                COVANCE VARIABLE COMPENSATION PLAN BUSINESS UNITS
                          FOR ACCRUALS AND BONUS POOLS


o    Global Labs

o    Global Phase I Clinics

o    Research Products

o    Global Central Labs & Central Diagnostics

o    ITMS

o    Nexigent

o    Global Clinical Phase II & III

o    Periapproval Services

o    CHEOS

o    Corporate
<PAGE>

                                                                      Appendix 2

                             Effect of Business Unit
                             -----------------------
                        Performance on Individual Payouts
                        ---------------------------------


Employee categories shall be determined by the General Manager of each Business
Unit (except for Key Executive/Executive Management employees who shall be
determined by the Global Leadership Council). Category guidelines and payout
percentages are set forth below.

     Individual Contributor* - generally defined as:

     1.  Clerical, administrative, support-type positions
     2.  For US employees - Non-exempt status
     3.  No supervisory responsibilities
     4.  Generally, employees at a target bonus of five percent or less

<TABLE>
<CAPTION>
     -------------------------------------------------------------------------------------------
         Business Unit Pre-Bonus Operating Margin          Percentage Bonus Payout of Target

     -------------------------------------------------------------------------------------------
<S>                                                                      <C>
            Less than 90% of target                                       80%
     -------------------------------------------------------------------------------------------
            90% to 110% of target                                        100%
     -------------------------------------------------------------------------------------------
            More than 110% of target                                     120%
     -------------------------------------------------------------------------------------------
*Individual performance assessment does not influence payout
</TABLE>

     Manager/Supervisor - generally defined as:

     1.  Professional, managerial and/or technical expertise
     2.  For US employees, Exempt status
     3.  May have supervisory responsibilities
     4.  Employees for whom clear personal objectives are set
     5.  Leadership position within the business unit

<TABLE>
<CAPTION>
     -------------------------------------------------------------------------------------------
         Business Unit Pre-Bonus Operating Margin          Percentage Bonus Payout of Target

     -------------------------------------------------------------------------------------------
<S>                                                                      <C>
            0% to 80% of target                                           75%
     -------------------------------------------------------------------------------------------
            100% of target                                               100%
     -------------------------------------------------------------------------------------------
            120% of target                                               125%**
     -------------------------------------------------------------------------------------------
</TABLE>

     Key Executive/Executive Management - Corporate Officers and select senior
     management employees to be determined annually by the Global Leadership
     Council (GLC).

<TABLE>
<CAPTION>
     -------------------------------------------------------------------------------------------
         Business Unit Pre-Bonus Operating Margin          Percentage Bonus Payout of Target

     -------------------------------------------------------------------------------------------
<S>                                                                      <C>
            0% to 80% of target                                           65%
     -------------------------------------------------------------------------------------------
            100% of target                                               100%
     -------------------------------------------------------------------------------------------
            115% or greater of target                                    125%
     -------------------------------------------------------------------------------------------
     *  Incremental payout rate between minimum and maximum is linear for the
        Manager/Supervisor and Key Executive/Executive Management categories.
     ** The maximum for Senior Managers is exclusive of any payouts under the
        Special Incentive Pool.
</TABLE>
<PAGE>

                                                                      Appendix 3

                 Designated Employee Performance Categories and
                 ----------------------------------------------
                       Performance Attainment Percentages
                       ----------------------------------


<TABLE>
<CAPTION>
     -------------------------------------------------------------------------------------------------

            Rating             Needs             Achieves            Exceeds           Outstanding
                            Improvement        Expectations        Expectations
     -------------------------------------------------------------------------------------------------
         Performance
<S>                           <C>                <C>                <C>                 <C>
         Attainment %         0 - 80%            80 - 110%          110 - 130%          130 - 160%
     -------------------------------------------------------------------------------------------------
</TABLE>