<PAGE>
                                                                   Exhibit 10.21


                               SERVICE AGREEMENT

                                    between

                    INVERESK RESEARCH INTERNATIONAL LIMITED

                                      and

                                   W.S. NIMMO

                           [DICKSON MINTO W.S. LOGO]

                               DICKSON MINTO W.S.
                                11 Walker Street
                                   Edinburgh
                                    EH3 7NE
<PAGE>
AGREEMENT between

1.       INVERESK RESEARCH INTERNATIONAL LIMITED, a Company incorporated in
         Scotland under the Companies Acts (Registered No. 91725) and having its
         registered office at Tranent EH33 2NE (hereinafter called "the
         Company"); and

2.       WALTER S. NIMMO of 26 Stafford Street, Edinburgh (hereinafter called
         the "Executive").

WHEREAS the Executive is a director of and is employed by the Company and it is
desired to regulate the terms of the Executive's employment with the Company.

NOW IT IS HEREBY AGREED as follows:-

1.       APPOINTMENT

         The Company agrees to employ the Executive and the Executive agrees to
         act as Chief Executive of the Company ("the Appointment") and the
         Executive agrees to serve the Company upon the terms set out in this
         Agreement.

2.       PERIOD

         The Appointment on the basis set out in this Agreement shall commence
         on 20th September 1999 and is continuous with the employment of the
         Executive since 1st November 1988 and shall continue until terminated
         by either party giving to the other not less than twelve months
         previous notice in writing to that effect.

3.       DUTIES OF EXECUTIVE

         During the continuance of the Appointment the Executive:

         (a)      shall devote the whole of his working time, attention and
                  skill to the duties of his office and shall faithfully,
                  efficiently, competently and diligently perform such
                  appropriate duties and exercise such powers as may from time
                  to time be assigned to or vested in him and shall obey all
                  reasonable and lawful
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                                       2.


                  directions given to him by or under the authority of the Board
                  and use his best endeavours to promote and extend the
                  Company's business and to protect and further the interests
                  and reputation of the Company;

         (b)      may be required in pursuance of his duties hereunder to
                  perform services not only for the Company but also for any
                  Group Company for so long as the Company reasonably requires
                  and to accept such offices in any subsidiary company as the
                  Company may from time to time reasonably require and the
                  Executive shall carry out such duties as if they were duties
                  to be performed by him on behalf of the Company and the
                  obligations contained herein shall apply mutatis mutandis as
                  if all references to "the Company" are references to the
                  relevant subsidiary company;

         (c)      hereby warrants to the Company that he shall not, as a
                  consequence of carrying out his duties hereunder, or entering
                  into this Agreement or other agreements or arrangements made
                  or to be made between the Company or any Group Company and him
                  commit any breach of any terms express or implied (whether
                  concerning confidentiality, non-competition or otherwise) of
                  any contract with or of any other obligation to any third
                  party binding upon him;

         (d)      shall not during the term of this Agreement (except with the
                  prior consent in writing of the Board such consent not to be
                  unreasonably withheld) be directly or indirectly engaged or
                  concerned in the conduct of any other business which is wholly
                  or partly in competition with any business carried on by the
                  Company or any Group Company whether by himself or in
                  partnership with or as agent, employee or representative of
                  any
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                                       3.

                           third party nor shall he be directly or indirectly
                           interested in any such business save through his
                           holding or being interested in investments (quoted or
                           unquoted) not representing more than three percent of
                           the issued securities of any class of any one
                           company;

                  (e)      shall at all times keep the Board promptly and fully
                           informed (in writing if so requested) of his conduct
                           of the business or affairs of the Company or any
                           Group Company and provide such further information,
                           written records and/or explanation as the Board may
                           require;

                  (f)      may be required in pursuance of his duties hereunder
                           to travel and stay on a temporary basis outside the
                           United Kingdom (not exceeding 8 weeks in any calendar
                           year unless otherwise agreed), but shall not, without
                           his consent, be required to reside outside the United
                           Kingdom; and

                  (g)      shall conform to such hours of work as may from time
                           to time reasonably be required of him and shall not
                           be entitled to receive any additional remuneration
                           for work outside the normal hours.

4. SALARY AND BENEFITS

                  During the continuance of the Appointment:-

                  (a)      the Company shall pay to the Executive a salary at
                           the rate of ONE HUNDRED AND FOUR THOUSAND FIVE
                           HUNDRED POUNDS (L104,500) per annum or such higher
                           rate as may from time to time be agreed, such salary
                           shall be subject to review on 1st January in each
                           year (such review not to be downward) and shall be
                           inclusive of any other remuneration from the Company
                           or any Group Company including, without prejudice to
                           the above generality, any fees receivable by the
                           Executive as a
<PAGE>
                                       4.

                           director of the Company or any Group Company. The
                           said salary (less tax and statutory deductions) shall
                           be payable to the Executive by equal monthly payments
                           in arrears on the last Thursday of each month and
                           shall be deemed to accrue on a daily basis;

                  (b)      the Company shall refund to the Executive, subject
                           where appropriate to the production of vouchers, all
                           out-of-pocket or other expenses properly incurred by
                           him in the performance of his duties including (but
                           not limited to) expenses of entertainment,
                           subsistence and travelling and where the Company
                           issues a company sponsored credit or charge card the
                           Executive shall use such card only for those expenses
                           reimbursable in terms of this sub-Clause 4(b), and
                           the Company reserves the right in its absolute
                           discretion to withdraw the use of such card(s) from
                           the Executive at any time without assigning any
                           reason therefor;

                  (c)      the Executive shall be entitled without loss of
                           remuneration to 33 working days holiday in each year
                           (in addition to Bank and other public holidays
                           notified from time to time by the Company) to be
                           taken at such time or times as the Company may
                           approve. Neither Saturday nor Sunday shall be
                           regarded as a working day;

                  (d)      without prejudice to the Company's rights under
                           Clause 8 below during any period of absence from work
                           due to sickness or accident the Executive shall
                           (after giving the Company when required evidence
                           satisfactory to it of incapacity and continuing
                           incapacity to work) be paid in full for the first
                           twenty-eight weeks of such absence. In each case
                           there shall be deducted from the Executive's
                           remuneration the amount of income benefit
<PAGE>
                                       5.

                           which he is entitled to claim in consequence of such
                           sickness or accident under the National Insurance
                           scheme for the time being in force (whether such
                           income benefit is received or not) and/or any scheme
                           for the time being in force of which by virtue of his
                           employment with the Company he is a non-contributory
                           member provided that after the period of
                           twenty-eight weeks the payment of salary shall be at
                           the discretion of the Company;

                  (e)      (i)      Subject to the rules for the time being
                                    applicable, the Executive shall be entitled
                                    to continue membership or become a member
                                    (as the case may be), and during the
                                    continuance of the Appointment remain a
                                    member of, the Company's pension scheme,
                                    known as the Inveresk Research International
                                    Pension and Life Assurance Plan, or any
                                    other executive, senior or other pension
                                    scheme for the time being in force which
                                    might be applicable to him, particulars of
                                    which are available from the Company
                                    Secretary ("the Scheme");

                           (ii)     the Company shall contribute to the Scheme
                                    at such rate as required to accrue for the
                                    Executive a pension entitlement of not less
                                    than 1/30th of final salary for each year of
                                    employment with the Company;

                           (iii)    the Company shall be entitled at any time to
                                    amend or terminate the Scheme referred to in
                                    Clause 4(e)(i) or the Executive's membership
                                    of it subject to (i) providing him with the
                                    benefit of an equivalent pension scheme
                                    ("the New Scheme") which shall be no less
                                    favourable overall to the Executive and (ii)
                                    ensuring that the Executive is in a
                                    position, if he so elects, to transfer his
                                    accrued benefits in the Scheme
<PAGE>
                  6.

                  into the New Scheme, as if such pensionable service had been
                  under the New Scheme;

         (iv)     changes in the rules of any pension scheme from time to
                  time in force will be notified in writing to the Executive
                  within one month of such change becoming effective and copies
                  of the rules of any such pension scheme will be made available
                  to him on application to the Company Secretary;

      (f)   the Company shall pay the premiums and other cost associated with
            the provision of permanent health insurance for the Executive at a
            level which is calculated to provide the Executive with not less
            than 65% of the annual salary payable to the Executive in terms
            of sub-Clause 4(a) hereof provided that there shall be deducted from
            the Executive's remuneration the amount of income benefit which he
            is entitled to claim in consequence of such sickness or accident
            under the National Insurance Scheme for the time being in force;

      (g)   the Company shall pay the premiums and other costs associated with
            the provision of private medical insurance for the Executive and
            his immediate family at a level which is in accordance with Company
            policy from time to time; and

      (h)   the Company shall pay the premiums and other costs associated with
            the provision of death-in-service insurance for the Executive at a
            level calculated to provide not less than four times the annual
            salary payable to the Executive in terms of sub-Clause 4(a) hereof.


<PAGE>


                                               7.

5. OTHER BENEFITS

      (a)   Motor Car

            For the purpose of enabling the Executive properly to
            perform his duties hereunder the Company, at the sole discretion of
            the Executive, shall either (i) provide him with the use of a motor
            car for a leasing cost of up to L465 per month excluding Value Added
            Tax or (ii) provide him with a car allowance of L8,000 per annum
            (each such sum to be subject to annual review), and in either event
            with a fuel card in respect of both business and private fuel.

      (b)   Clothing Allowance

            The Company shall provide the Executive with an annual clothing
            allowance of L205 per annum plus Value Added Tax, such sum
            to be subject to annual review.

      (c)   Telephone Allowance

            The Company shall provide the Executive with a telephone allowance
            of L38 per month (inclusive of Value Added Tax), such sum to be
            subject to annual review.

      (d)   Bonus

            (i)   The Executive shall be entitled to a corporate performance
                  bonus ("CPB"). The CPB shall be payable quarterly at a rate of
                  such percentage of the Executive's Salary in terms of Clause
                  4(a) hereof as may be determined by the Board of the Company;
                  and

            (ii)  the Executive shall be entitled to a personal bonus on the
                  terms set out in a letter dated 16th February 1999 from I.P.
                  Sword to the Executive and shall further be entitled to
                  participate in an annual successor arrangement to such
                  personal bonus on terms similar


<PAGE>


                                       8.

                  to the terms of the personal bonus to be agreed between the
                  Executive and the Board prior to 31st December in each year;
                  and

            (iii) the Executive shall be entitled to a loyalty bonus on the
                  terms set out in a letter dated 23rd March 1999 from I.P.
                  Sword to the Executive.

6. NON-DISCLOSURE OF CONFIDENTIAL INFORMATION

      (a)   The Executive shall not directly or indirectly divulge or
            communicate to any person (other than those within the employment of
            the Company whose province it is to know the same or with the prior
            written authority of the Company or as otherwise required by
            law) nor shall he make use of (otherwise than for the purposes of
            performing his duties hereunder) any of the trade secrets, designs,
            techniques, design improvements, know-how, business information,
            methods, lists or other confidential information of the Company or
            of any Group Company or of their respective customers which he may
            (whether heretofore or hereafter) have received or obtained while in
            the service of the Company or of any Group Company or of any
            information in respect of which the Company or any Group Company is
            bound by an obligation of confidentiality to a third party
            ("Confidential Information"). This restriction shall continue to
            apply after the termination of the Appointment.

      (b)   The Executive shall use his best endeavours to prevent the
            publication or disclosure of any Confidential Information whether
            relating to trade dealings, financial affairs or otherwise.

      (c)   The restrictions contained in this Clause 6 shall cease to apply to
            any Confidential Information which may (otherwise than by
<PAGE>
                                                  9.

                  reason of the default of the Executive) become available to
                  the public generally.

          (d)     The Executive shall not during the continuation of the
                  Appointment make (otherwise than for the benefit of the
                  Company or any Group Company) any notes, memoranda, tape
                  recordings, films, photographs, plans, drawings or any form of
                  record relating to any matter within the scope of the business
                  of the Company or any Group Company or concerning any of the
                  dealings or affairs of the Company or any Group Company ("the
                  Company Records").

7.        INVENTIONS

          In view of the fact that the business of the Company and of the Group
          Companies consists in part in the development and exploitation of
          inventions, techniques, designs and methods and that it is the
          Executive's responsibility to further the interests of the Company and
          the Group Companies in respect thereof he agrees that each and every
          discovery, invention, improvement, design and secret process made or
          discovered by him (whether alone or with any other person or persons)
          at any time whether before or after the date hereof but after he
          became an employee of the Company whether capable of being patented or
          registered or not (and whether or not made or discovered in the course
          of his employment hereunder) in connection with or in any way
          affecting or relating to the business of the Company or of any Group
          Company or capable of being used or adapted for use therein or in
          connection therewith shall forthwith be disclosed to the Company and
          shall belong to and be the absolute property of the Company or such
          Group Company as the Company may nominate for the purpose. If and
          whenever required so to do (whether during or after the termination of
          the Appointment) the Executive shall at the expense of
<PAGE>


                                       10.



          the Company apply or join in or appoint the Company as his agent with
          full powers for the purposes of applying for letters patent or other
          equivalent protection in the United Kingdom or any other part of the
          world for any such discovery, invention, improvement, design and
          secret process as aforesaid and execute all instruments and do all
          things necessary for vesting the said letters patent or other
          equivalent protection when obtained and all right, title and interest
          to and in the same in the Company (or its nominees) absolutely and as
          sole beneficial owner or in such other person as the Company may
          require; provided always that nothing herein shall prejudice the
          rights of the Executive as contained in Sections 40 to 43 of the
          Patents Act 1977 as amended by the Copyright, Designs and Patents Act
          1988.

8.       TERMINATION

          (a)     Without in any way limiting any rights of the Company this
                  Agreement shall be subject to termination by the Company by
                  summary notice in writing given at any time if the Executive:-

                  (i)         if the Executive shall have committed any serious
                              or material breach (whether by one or several acts
                              or omissions) of his obligations hereunder; or

                  (ii)        shall have been guilty of conduct to bring him or
                              the Company or any Group Company into disrepute;
                              or


                  (iii)       shall have been found guilty of any criminal
                              offence (other than an offence under the Road
                              Traffic Acts from time to time in force); or

                  (iv)        shall have become of unsound mind or lunatic; or


                  (v)         shall have committed any act of bankruptcy or
                              shall have taken advantage of any statute for the
                              time being in force offering relief for insolvent
                              debtors.

<PAGE>

                                      11.

          (b)       If the Company has any grounds to believe it may have a
                    right to terminate the Appointment of the Executive pursuant
                    to sub-Clause (a) above, it shall be entitled (but without
                    prejudice to its right subsequently to terminate the
                    Appointment on the same or any other ground) to suspend the
                    Executive on full payment of salary and other benefits
                    during the period of any enquiry or investigation into the
                    circumstances giving rise to such belief.


          (c)       Without prejudice to the rights of the Executive to
                    remuneration and other benefits hereunder and to the rights
                    of the Company hereunder including, without prejudice to the
                    foregoing generality, sub-Clause 8(b) and Clause 6, the
                    Company shall have the right at any time after either party
                    has given notice to the other of termination of this
                    Agreement in terms of Clause 2 hereof until such termination
                    to require the Executive not to attend at any place of work
                    and to exclude him from any premises of the Company (or any
                    Group Company in relation to which the Executive held a
                    position of responsibility at any time during the twelve
                    months immediately prior to the date on which notice is
                    served pursuant to Clause 2) and the Company shall be under
                    no obligation to vest in or assign to the Executive any
                    powers or duties or to provide any work for the Executive
                    and shall have the right to suspend him from the performance
                    of any duties or obligations hereunder (provided that the
                    rights of the Company pursuant to this sub-Clause 8(c) shall
                    not be exercised for a period exceeding twelve months in
                    aggregate) and the Executive shall at the request of the
                    Company resign without claim for compensation from any
                    office of director or otherwise held by him in the Company
                    or in any Group Company.

<PAGE>
                                      12.

         (d)      Following the service of notice by either party in accordance
                  with Clause 2 the Company may terminate the Appointment
                  forthwith by paying salary and the value of all other
                  contractual benefits in lieu of the required period of notice
                  (but without prejudice to the Company's rights under Clause 10
                  of this Agreement) and it is expressly agreed and declared
                  that such payment in lieu of notice shall not constitute a
                  repudiation of this Agreement.

         (e)      Termination of the Executive's appointment hereunder howsoever
                  and for whatever reason and whether lawfully or otherwise
                  shall be without prejudice to any rights which have accrued to
                  the Company at the time of termination or to the provisions of
                  Clauses 6,9 and 10 which shall remain in full force and
                  effect.

9.       PROVISIONS ON TERMINATION

         (a)      On the termination of the Appointment (which term, for the
                  purposes of the Agreement as a whole, shall mean termination
                  of the Appointment irrespective of the cause or manner,
                  including, for the avoidance of doubt, by reason of a
                  repudiatory breach of the Agreement by the Company) or any
                  time thereafter the Executive shall at the request of the
                  Company resign without claim for compensation from any office
                  of director or otherwise held by him in the Company or in any
                  Group Company and transfer without payment to the Company any
                  shares held by the Executive as a nominee on behalf of the
                  Company or any Group Company.

         (b)      All property of, or relating to, the Company or any Group
                  Companies as shall have been in the possession of the
                  Executive shall be surrendered by him to someone duly
                  authorised by the
<PAGE>
                                      13.

                  Company upon the termination of the Appointment or the
                  suspension of the Appointment in accordance with sub-clause
                  8(b) or sub-Clause 8(c) or at the request of the Board at any
                  time during the course of his employment hereunder.

10.      NON-COMPETITON.

         10.1     As the Executive, in the course of his employment and
                  directorship, is likely from time to time to obtain knowledge
                  of trade secrets and other confidential information of Group
                  Companies and to have dealings with the customers and
                  suppliers of Group Companies and in order to protect such
                  trade secrets and other confidential information and the
                  goodwill of Group Companies, the Executive undertakes to the
                  Company in the terms of Clause 10.2.

         10.2     The Executive undertakes to the Company that, without
                  prejudice to any other duty implied by law or equity, he will
                  not, for a period of 12 months (the "Restricted Period") after
                  he ceases to be either an employee of, or a consultant to, any
                  Group Company and does not continue in any such capacity (the
                  "Termination Date");

                  10.2.1   be concerned in any business which competes with any
                           business of any Group Company as carried on at the
                           Termination Date (and in which the Executive was
                           actively involved during the 12 months ending on the
                           Termination Date) in any territory in which such
                           business was carried on at such date;

                  10.2.2   directly or indirectly on his own account or on
                           behalf of or in conjunction with any person (except
                           on behalf of a Group Company) canvass or solicit
                           business or custom for goods of a similar type to
                           those being manufactured or dealt in or services
                           similar to those being provided by any Group Company
                           at the Termination Date and with which the Executive
                           was actively involved in the course of his employment
                           during the 12 months
<PAGE>
                                      14.

                           ending on the Termination Date from any person who
                           has been at any time during the 12 months ending on
                           the Termination Date a customer or client of any
                           Group Company and with whom the Executive was
                           actively involved in the course of his employment
                           during the 12 months ending on the Termination Date;

                  10.2.3   directly or indirectly on his own account or on
                           behalf of or in conjunction with any person induce or
                           attempt to induce any supplier of any Group Company,
                           with whom the Executive was actively involved in the
                           course of his employment during the 12 months ending
                           on the Termination Date, to cease to supply, or to
                           restrict or vary the terms of supply to, any Group
                           Company or otherwise interfere with the relationship
                           between such a supplier and any Group Company;

                  10.2.4   directly or indirectly on his own account or on
                           behalf of or in conjunction with any person induce or
                           attempt to induce any employee of any Group Company
                           who is engaged in any business or activity carried on
                           by a Group Company at the Termination Date, and with
                           whom the Executive during the 12 months ending on the
                           Termination Date had material dealings in the course
                           of his employment, to leave the employment of that
                           Group Company (whether or not this would be a breach
                           of contract by the employee); or

                  10.2.5   use or (insofar as he can reasonably do so) allow to
                           be used (except by a Group Company) any trade name
                           used by any Group Company at the Termination Date, or
                           any other name calculated or likely to be confused
                           with such a trade name.

         10.3     The Company and the Executive agree that the foregoing
                  restrictions shall apply even in circumstances where the
                  relevant Executive was

<PAGE>
                                       15.


      made redundant or was constructively or unfairly or wrongfully dismissed
      as determined in accordance with the provisions of Clause 10.4 below
      provided that in such circumstances the Company shall pay to the Executive
      each month during the Restricted Period a sum equal to the monthly
      remuneration to which he was entitled immediately prior to the
      termination.

10.4  Without prejudice to the Executive's rights to claim constructive and/or
      wrongful and/or unfair dismissal, for the purposes of determining whether
      the Executive has been constructively and/or unfairly and/or wrongfully
      dismissed solely for the purposes of Clause 10.3 of this Agreement the
      Executive or the Company may request the appointment of an independent
      solicitor to determine whether the Executive has been constructively
      and/or unfairly and/or wrongfully dismissed. Such appointment shall be
      made by the Executive and the Company either jointly or, in default of an
      agreement within seven days of one party notifying the other of its wish
      to appoint an independent solicitor, by the President for the time being
      of the Law Society of England and Wales on the application of either
      party. The certification prepared by such independent solicitor shall be
      final and binding on the Executive and the Company for the purposes of
      this Clause 10. Such independent solicitor shall act as an expert and not
      as an arbiter. The Company shall pay the charges of any independent
      solicitor appointed in accordance with this Clause 10.4 unless the
      independent solicitor determines that the Executive was not
      constructively, unfairly or wrongfully dismissed in which case the costs
      shall be borne by the Executive.

10.5  The restrictions set out in Clause 10.2 above shall apply to any action
      taken by the Executive whether as agent, representative, principal,
<PAGE>
                                       16.

      employee or consultant or as a director of any company and/or by any
      company controlled by him.

10.6  The Executive acknowledges and agrees that each of paragraphs 10.2.1 to
      10.2.5 of this Clause 10 constitutes an entirely separate and independent
      restriction on him and that the duration, extent and application of each
      of the restrictions are no greater than is necessary for the protection of
      the interests of the Company and the Group Companies.

10.7  While the restrictions aforesaid are considered by both parties to be
      reasonable in all the circumstances it is recognised that restrictions of
      the nature in question may fail for technical reasons unforeseen and
      accordingly it is hereby declared and agreed that if any of such
      restrictions shall be adjudged to be void as going beyond what is
      reasonable in all the circumstances for the protection of the interests of
      the Company and the Group Companies but would be valid if part of the
      wording thereof were deleted the said restrictions shall apply with such
      deletion as may be necessary to make them valid and effective.

10.8  In the event that the Executive is suspended under Clause 8(d) from the
      performance of his duties, for the purposes of this Clause 10 the
      "Termination Date" shall be the date on which the Executive is first so
      suspended.

11.   AUTHORITY OF THE COMPANY

      The Executive hereby irrevocably appoints the Company to be his authorised
      attorney to do all such things and to execute all such documents in his
      name and on his behalf as may be necessary to secure that the full benefit
      and advantage of the rights arising under Clause 7 and sub-clauses 9(a)
      and (b) hereof are obtained by the Company (or where appropriate its
      nominee) and a letter signed by any Director or
<PAGE>
                                       17.

      Secretary of the Company certifying that anything or any document has been
      done or executed within the authority hereby conferred shall be conclusive
      evidence of the same.

12.   DEFINITIONS

      In this Agreement words and phrases defined in Section 736 of the
      Companies Act 1985 (as amended) shall bear the same meaning and the
      expression "Board" means the directors of the Company present at a meeting
      of the directors or of a committee of the directors duly convened and
      held, the expression "Parent" means Inveresk Research Group Limited a
      company incorporated in Scotland with registered number 198026 and the
      expression "Group Companies" means the Parent and its subsidiary companies
      from time to time and Group Company means any one of them.

13.   NOTICES

      Notices may be given by either party by first class prepaid recorded
      delivery letter or by facsimile transmission addressed to the other, or by
      delivery at (in the case of a notice to the Company) its registered office
      for the time being and (in the case of a notice to the Executive) his last
      known address and in the case of a letter shall be deemed to have been
      given 48 hours after posting and in the case of facsimile transmission or
      delivery shall be deemed to have been given at 9.00 a.m. on the business
      day following transmission or delivery as the case may be.

14.   EMPLOYMENT RIGHTS ACT

      The information contained herein and in the Schedule hereto constitutes a
      written statement of the terms of the Executive's employment in compliance
      with the provisions of the Employment Rights Act 1996.
<PAGE>
                                      18.


15.      SURVIVAL OF AGREEMENTS

         The expiration or determination of this Agreement howsoever arising
         (including, for the avoidance of doubt, by reason of a repudiatory
         breach by the Company) shall not operate to affect such of the
         provisions hereof as in accordance with their terms are expressed to
         operate or have effect thereafter.

16.      ENTIRE AGREEMENT

         This Agreement is in substitution for all previous contracts of service
         between the Company or any Group Company and the Executive which shall
         be deemed to have been terminated be mutual consent as from the date
         on which this Agreement is deemed to have commenced. The Executive
         acknowledges that he has no claim against the Company or any Group
         Company (or against any of their respective assets) arising under or
         out of any such contract or arrangement other than for accrued salary
         and bonus entitlements. The Executive and the Company each acknowledge
         that this Agreement constitutes the whole and only agreement between
         the parties in relation to the employment of the Executive with the
         Company and in entering into this Agreement neither party is relying on
         any undertaking, representation, warranty, promise or other assurance
         of any other person made on or prior to the date of this Agreement
         which is not set out herein.

17.      NON-WAIVER

         No failure of the Company to exercise, nor any delay in exercising, any
         right hereunder shall operate as a waiver of that or any other right or
         remedy of the Company, nor shall any partial exercise preclude any
         further or other exercise.
<PAGE>
                                      19.


18.      PROPER LAW

         This Agreement shall be governed by and construed in accordance with
         the Law of Scotland.

IN WITNESS WHEREOF these presents consisting of this and the eighteen preceding
pages and the Schedule hereto are executed as follows:-


SIGNED on behalf of INVERESK                    /s/ Ian P. Sword
RESEARCH INTERNATIONAL                          -----------------------------
LIMITED by I. Sword                             Director
and S. Leslie, both directors
at Edinburgh on the 20th                        /s/ Stewart Leslie
day of September Nineteen                       -----------------------------
hundred and Ninety Nine.                        Director


SIGNED by the said WALTER S. NIMMO
at Edinburgh on the 20th                        /s/ Walter S. Nimmo
day of September Nineteen                       -----------------------------
hundred and Ninety Nine before                  W.S. Nimmo
this witness:-


/s/ Ewan C. Gilchrist
-------------------------
Ewan C. Gilchrist        Full Name
-------------------------
11 Walker St.            Address
-------------------------
Edinburgh
-------------------------
Solicitor
-------------------------
Occupation
<PAGE>
                                      20.


                                  THE SCHEDULE
                           EMPLOYMENT RIGHTS ACT 1996

THE EMPLOYER            Inveresk Research International Limited

THE EMPLOYER/           Walter S. Nimmo
EXECUTIVE

APPOINTMENT             Chief Executive

PERIOD OF               From 1st November 1988 and ending on 12 months notice
APPOINTMENT             from either party. Previous employment with any Group
                        Company does count as part of continuous employment for
                        statutory purposes.

SALARY                  L104,500 per annum subject to agreement and review on
                        1st January in each year and payable monthly in arrear
                        on the last Thursday of each calendar month.

HOURS OF WORK           The normal hours of work are currently from 9:00 a.m. to
                        5:00 p.m. (Monday to Friday) inclusive of 45 minutes for
                        lunch daily. The Executive is expected to work
                        reasonable overtime when necessary for the performance
                        of his/her duties without additional remuneration.

HOLIDAYS                33 working days in any calendar year and such Bank or
                        public holidays as the Company may approve.

PENSION                 There is a contracting-out certificate in relation to
                        the employment.

REDRESS OF              The grievance procedure currently in force and any
GRIEVANCE &             disciplinary rules applicable to the Executive will be
DISCIPLINARY            set out from time to time in notices displayed at
PROCEDURE               his/her place of work or will otherwise be obtainable
                        from the Company.



/s/ Ian P. Sword                                   /s/ W.S. Nimmo
-----------------------------                      -----------------------------
Dir                                                WSN


/s/ Stewart Leslie
-----------------------------

Dir