DATED 3rd JUNE 1999












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                       THE HUNTINGDON LIFE SCIENCES GROUP

                         UNAPPROVED SHARE OPTION SCHEME

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                                         Charles Russell
                                      8-10 New Fetter Lane
                                         London EC4A 1RS




<PAGE>


                                              INDEX


                                  (for reference purposes only)


Rule     Heading                                             Page Number


1.       DEFINITIONS AND INTERPRETATION                          1
         ------------------------------

2.       GRANT OF OPTIONS                                        7
         ----------------

3.       SCHEME LIMITS                                          11
         -------------

4.       PERSONAL LIMITS                                        12
         ---------------

5.       EXERCISE AND LAPSE OF OPTIONS                          13
         -----------------------------

6.       TAKEOVERS AND LIQUIDATIONS                             15
         --------------------------

7.       VARIATION OF SHARE CAPITAL                             17
         --------------------------

8.       MANNER OF EXERCISE OF OPTIONS                          17
         -----------------------------

9.       TAXATION                                               18
         --------

10.      ADMINISTRATION AMENDMENT AND TERMINATION               19
         ----------------------------------------

SCHEDULE 1                                                      21
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SCHEDULE 2                                                      23
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SCHEDULE 3                                                      24
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<PAGE>


                   RULES OF THE HUNTINGDON LIFE SCIENCES GROUP


                         UNAPPROVED SHARE OPTION SCHEME


                           Adopted on 2 September 1998
                           and amended on 3 June 1999


1.       DEFINITIONS AND INTERPRETATION


1.1      In these Rules the following words and expressions  shall (except where
         the context otherwise requires) have the following meanings:


         "Act"                     the Companies Act 1985;


         "Accounting Period"       an accounting reference period of the
                                   Company;


         "Announcement Date"       the  date  on  which  the  annual  or  half-
                                   yearly results of the Company are announced;


         "Appropriate Period"     (i)      if  the  circumstances  in  Rule  6.1
                                           apply  the period of six months
                                           beginning  with the date on
                                           which the person  making  the offer
                                           has  obtained Control  of the Company
                                           and  any  condition subject to which
                                           the  offer  is made  has been
                                           satisfied;


                                  (ii)     if  the  circumstances  in  Rule 6.2
                                           apply  the period of six months
                                           beginning  with the date on
                                           which the  Reconstruction  Scheme is
                                           sanctioned by the Court;


                                  (iii)    if the circumstances in Rule 6.3
                                           apply the period during which  the
                                           person  remains  bound  or entitled
                                           to acquire any shares in the Company;

         "Associated Company"              the same meaning as in Section 416 of
                                           the Taxes Act;


         "Auditors"                        the auditors  for the time being of
                                           the Company  appointed pursuant  to
                                           section 384 of the Act and acting as
                                           experts and not as arbitrators;


         "Board"                           the Board of directors  for the time
                                           being of the  Company  or a duly
                                           appointed  committee  thereof at
                                           which a quorum  is present;


         "Company"                         Huntingdon   Life  Sciences   Group
                                           plc   (registered  in
                                           England and Wales number 502370);


         "Company                          Share  Schemes"  the Scheme
                                           and any other share  option
                                           or  profit   sharing  share
                                           scheme of the Company or of
                                           any   Associated    Company
                                           whether or not  approved by
                                           the Inland Revenue;


         "Control"                         the same  meaning as in  Section 840
                                           of the Taxes Act and the  expression
                                           "controlled"  shall be construed
                                           accordingly;


         "Date of Adoption"                2  September  1998  being  the date
                                           of  adoption  of this
                                           Scheme by the Company;


         "Date of Grant"                   in  relation  to any  Option  means
                                           the date on which the Option is
                                           granted or was or is to be granted
                                           under the Scheme;


         "Dealing Day"                     a day on  which  the  London  Stock
                                           Exchange  is open for business;

         "Earnings per share"             earnings  per share  normalised after
                                          disregarding  any exceptional  or
                                          extraordinary  items as shown in the
                                          Company's   audited  accounts  for an
                                          Accounting  Period ("normalised
                                          earnings  per  share") provided that
                                          if in relation to any  Accounting
                                          Period the Company's audited
                                          accounts do not contain an  earnings
                                          per share figure or if the accounting
                                          reference  date of  the  Company  is
                                          changed  the   normalised   earnings
                                          per  share  for  an Accounting  Period
                                          determined   by   the   Remuneration
                                          Committee  in  consultation  with the
                                          Auditors  or  such  other  advisers
                                          as the  Remuneration  Committee may in
                                          its absolute discretion select;


         "Eligible Participant"     (a)   an employee who is a director of a
                                          Participating Company who is required
                                          by his contract of employment to
                                         devote
                                          substantially  the  whole  of  his
                                          working  time  to the business of the
                                          Group; or


                                    (b)   any  other  employee  of a
                                          Participating  Company  who is
                                          required  by  his   contract  of
                                          employment   to  devote
                                          substantially  the  whole  of  his
                                          working  time  to  the
                                          business of the Group;


         "Exceptional Performance           an Option designated as such under


         Option"                            Rule 2.3.4;


         "Expected                        Retirement  Date"  the date
                                          on   which   an    Eligible
                                          Participant  is expected to
                                          retire in  accordance  with
                                          the  terms of his  contract
                                          of   employment    with   a
                                          Participating Company;


         "Founder                         Option"  an option  granted
                                          under     Rule    2.1    as
                                          appropriate  an 'A' Option,
                                          a 'B' Option,  a 'C' Option
                                          or a 'D' Option;


         "Group"                          the Company and any company under the
                                          Control of the Company


         "London Stock Exchange"          the London Stock Exchange Limited;


         "Market Value"                   in respect of any Share on any day
                                          means either:


                                           (a)      (when  on that day
                                                    the shares of that
                                                    class  are  listed
                                                    on  the   official
                                                    list of the London
                                                    Stock    Exchange)
                                                    the middle  market
                                                    quotation  of such
                                                    a Share as derived
                                                    from   the   Daily
                                                    Official  List  of
                                                    the  London  Stock
                                                    Exchange  for  the
                                                    Dealing        Day
                                                    immediately
                                                    preceding     that
                                                    day; or


                                           (b)      in all other cases
                                                    the  market  value
                                                    of such a Share as
                                                    determined      in
                                                    accordance    with
                                                    the  provisions of
                                                    part  VIII  of the
                                                    Taxation        of
                                                    Chargeable   Gains
                                                    Act 1992;


         "Option"                          a right to  subscribe  for Shares
                                           granted  (or to be  granted)  in
                                           accordance  with  these  Rules and
                                           where  the  context  so
                                           requires  shall include a Founder
                                           Option,  an Exceptional
                                           Performance    Option   and   New
                                           Options   granted   as
                                           consideration   for  the   release
                                           of  Old   Options  in
                                           accordance with Rule 6;


         "Option Agreement"               the  agreement  dated 2  September
                                          1998 and made  between
                                          the Company (1) and Andrew H Baker(2);


         "Option                            Holder"  any person who has
                                            been  granted  an Option or
                                            where the context  requires
                                            a person becoming  entitled
                                            to an Option in consequence
                                            of the  death of an  Option
                                            Holder;


         "Option                            Period"  in  respect of any
                                            Option,    other   than   a
                                            Founder  Option  the period
                                            between  the  Date of Grant
                                            and the first date on which
                                            the     Option      becomes
                                            exercisable  in  accordance
                                            with    the     Performance
                                            Conditions   set   by   the
                                            Remuneration      Committee
                                            pursuant to Rule 2.7, 2.10;


         "Participating                     Company"  the  Company  and
                                            any other  company of which
                                            the Company has Control and
                                            which is for the time being
                                            authorised      by      the
                                            Remuneration  Committee  to
                                            participate in this Scheme;


         "Performance                       Conditions"  the conditions
                                            imposed by the Remuneration
                                            Committee  in respect of an
                                            Option,    other   than   a
                                            Founder Option, pursuant to
                                            Rule 2.7, 2.10;


         "Remuneration                      Committee"   the  committee
                                            consisting wholly or mainly
                                            of non-executive  directors
                                            of the  Company and chaired
                                            by a non-executive director
                                            and      having      formal
                                            responsibility    for   the
                                            operation of the Scheme;


         "Rules"                            the  rules of the  Scheme as set out
                                            herein  and as  amended  from
                                            time to time;


         "Scheme"                           the  employee  share  option  scheme
                                            constituted  and  governed by
                                            these Rules as from time to time
                                            amended;


         "Share"                            an ordinary share of 5p in the
                                            capital of the Company;


         "Subscription                      Price"  the  price at which
                                            each  Share  subject  to an
                                            Option may be  acquired  on
                                            the exercise of that Option
                                            being (subject to Rules 6.4
                                            and  7) in  the  case  of a
                                            Founder  Option  12.5 pence
                                            per   Share  and  in  every
                                            other  case not lower  than
                                            the higher of:


                                            (i) the nominal value of a Share;
                                                and


                                            (ii)the  Market  Value  of a  Share
                                                on the  Date  of Grant;

         "Subsisting Option"                    an Option to the  extent that it
                                                has not been  exercised, lapsed
                                                or cancelled;


         "Tax                               Liability" any liability of
                                            the  Company or any company
                                            which  Controls or is under
                                            the  Control of the Company
                                            to  account  for any income
                                            tax   National    Insurance
                                            contributions  or other tax
                                            arising in  relation to the
                                            grant,  exercise  or  other
                                            dealing with or in relation
                                            to an Option;


         "Taxes Act"                        the Income and Corporation Taxes Act
                                            1988;


         "Total Remuneration"               in relation to any  Eligible
                                            Participant and in any period where
                                            that Eligible  Participant  is an
                                            employee or officer of a
                                            Participating  Company  the
                                            remuneration   (exclusive  of
                                            benefits  in  kind  but  for  the
                                            avoidance   of  doubt,
                                            including   any   cash   amount
                                            paid  to  the   Eligible
                                            Participant)    paid   or   payable
                                            to   that   Eligible
                                            Participant  by  the Participating
                                            Company   and  all
                                            Associated  Companies  of that
                                            Participating  Company  in
                                            that period; and


         "Year of Assessment"               a  year  beginning  on  any 6 April
                                            and ending on the following 5 April.


1.2      Any  reference in these Rules to any provision of any Act of Parliament
         or any subordinate  legislation  made pursuant to any Act of Parliament
         shall  be  deemed  to be a  reference  to  such  Act of  Parliament  or
         subordinate  legislation  as amended  modified or  re-enacted  (whether
         before or after the date hereof).


1.3      In these Rules words  incorporating  the masculine  gender only include
         the feminine and neuter  genders and words  incorporating  the singular
         number only include the plural and vice versa.


1.4      Rule headings are for ease of reference only and do not affect the
         construction or  interpretation  of these Rules.


1.5      References to writing shall include  typewriting  printing  lithography
         photography and facsimile messages and other modes of reproducing words
         in a legible and non-transitory form.


2.       GRANT OF OPTIONS


2.1      Subject to the limitations and conditions  hereinafter  contained,  the
         Remuneration  Committee  shall on or as soon as reasonably  practicable
         after the Date of Adoption grant,  without  consideration  four Options
         each at the  Subscription  Price and over an equal  number of Shares as
         shall be  determined  by the  Remuneration  Committee to such  Eligible
         Participants  selected at its  discretion and each such Option shall be
         designated  as an 'A'  Option,  a 'B'  Option,  a 'C'  Option and a 'D'
         Option  respectively  provided that no Founder  Option shall be granted
         after 31 December 1998.


2.2      The exercise of a Founder Option shall be subject to the following
         conditions:


         2.2.1    the  'A'  Option  shall  become  exercisable  on  the  seventh
                  consecutive  Dealing Day on which,  but not until,  the Market
                  Value of a Share is 25 pence per Share;


         2.2.2    the  'B'  Option  shall  become  exercisable  on  the  seventh
                  consecutive  Dealing Day on which,  but not until,  the Market
                  Value of a Share is 50 pence per Share;


         2.2.3    the  'C'  Option  shall  become  exercisable  on  the  seventh
                  consecutive  Dealing Day on which,  but not until,  the Market
                  Value of a Share is 75 pence per Share; and


         2.2.4    the  'D'  Option  shall  become  exercisable  on  the  seventh
                  consecutive  Dealing Day on which,  but not until,  the Market
                  Value of a Share is 100 pence per Share


         provided that the Market Value of a Share on any Dealing Day before 1st
         January  1999 shall be ignored in applying  the above  conditions  and,
         subject  to  Rules  5.4,  5.5,  5.6,  a  Founder  Option  shall  not be
         exercisable  before the third  anniversary of a Date of Grant.  For the
         avoidance of doubt a Founder  Option shall be exercisable in accordance
         with the  rules of this  Scheme  if the  condition  applicable  to that
         Founder  Option  under  this  Rule  2.2 has been  previously  satisfied
         regardless  of the  Market  Value of a Share  on the date on which  the
         Founder Option is exercised.


2.3      Subject  to  Rule  2.1  the  limitations  and  conditions   hereinafter
         contained and unless  prohibited by law the  Remuneration  Committee on
         behalf of the Company may, in its absolute discretion,  within a period
         of 42  days  immediately  following  an  Announcement  Date  or Date of
         Adoption grant without  consideration Options to any number of Eligible
         Participants provided that:


         2.3.1    no Eligible Participant shall be entitled as of right to the
                  grant of an Option;


         2.3.2    no Option (other than an Exceptional  Performance  Option) may
                  be granted to an Eligible Participant within 2 years preceding
                  his Expected  Retirement  Date and no Exceptional  Performance
                  Option may be granted to an Eligible  Participant within the 4
                  years preceding his Expected Retirement Date;


         2.3.3    no Option  may be  granted  under  this  Scheme  after the
                  tenth  anniversary  of the Date of Adoption; and


         2.3.4    an Option  may be  designated  as an  Exceptional  Performance
                  Option and for the avoidance of doubt an Eligible  Participant
                  may on the same day be  granted  two  Options  one of which is
                  designated as an Exceptional  Performance Option and the other
                  is not.


2.4      An Option shall be granted by a resolution of the Remuneration
         Committee.


2.5      Notwithstanding  the provisions of Rule 2.3 the Remuneration  Committee
         may grant  Options  outside  the 42 day  period  mentioned  therein  in
         circumstances   which  the  Remuneration   Committee  in  its  absolute
         discretion  deems  sufficiently  exceptional  to  justify  the grant of
         Options at that time.


2.6      An Option  Holder may,  within a period of twenty one days  immediately
         following  the Date of Grant,  renounce  by notice  in  writing  to the
         Company his Option in respect of all or any part of the Shares  subject
         of the Option and in which case that  Option  shall be deemed  never to
         have been granted to the extent so renounced.


2.7      Each Option,  other than a Founder Option, shall be granted so that its
         exercise  shall be subject to such objective  conditions  ("Performance
         Conditions")  (not  inconsistent with the provisions of the Scheme ) as
         the  Remuneration  Committee may in its absolute  discretion  think fit
         provided that:


         2.7.1     2.7.1.1  such  conditions  shall  be  designed  to
                              ensure  that the  exercise  of an  Option  is made
                              subject to the  attainment  of a  significant  and
                              sustained  improvement in the underlying financial
                              performance  of  the  Company  during  the  Option
                              Period;


                  2.7.1.2     such conditions shall not be inconsistent with the
                              provisions  of the  Scheme  and may be  waived  or
                              amended  if  an  event  occurs  which  causes  the
                              Remuneration   Committee  to  consider  that  such
                              Performance   Conditions   could  not   fairly  or
                              reasonably  be  met,  provided  that  any  amended
                              conditions  should be neither more  difficult  nor
                              easier to satisfy  than the  original  Performance
                              Conditions  were  intended  to be at the  time  of
                              their imposition;


                  2.7.1.3     such  conditions  shall extend over a continuous
                              period of at least three years; and

2.7.2    in the  case  of an  Exceptional  Performance  Option, such conditions
         shall  have  the  additional condition that over five  consecutive
         Accounting  Periods (or such number of  consecutive  Accounting
         Periods  that in  aggregate  consist  of a period  not less than 60
         months  if such five  consecutive Accounting  Periods in aggregate
         consist of less than 60 months)  commencing  with and  including the
         Accounting  Period  current  at the Date of  Grant,  the  growth  in
         Earnings  per  Share is at lease equivalent  to the growth in the
         normalised  earnings per share over such period of the company which
         on the last day of such  period is  ranked  at the  bottom of the
         companies  which  comprise  the top quartile  of the FTSE 100 Index
         capable of being  ranked for  growth in the  earnings  per share over
         such period as  determined by the  Remuneration  Committee in
         consultation  with the Auditors or such other advisers as the
         Remuneration Committee may in its absolute discretion select.


2.8      The  Remuneration  Committee  may in  its  absolute  discretion  impose
         conditions  on the grant of an  Option,  other  than a Founder  Option,
         restricting  the  number of Shares in respect of which an Option may be
         exercised on any one occasion.


2.9      As soon as reasonably  practicable  after Options have been granted the
         Board shall issue an Option  certificate  substantially in the form set
         out in Schedule 2 in respect of each Option which shall specify:


         2.9.1    the number of Shares comprised in the Option;


         2.9.2    the Date of Grant;


         2.9.3    the Subscription Price;


         2.9.4    save in the case of a Founder Option, details of the
                  Performance Conditions; and


         2.9.5    in the case of an Exceptional Performance Option that it has
                  been designated as such;


         2.9.6    the last date upon which  notice to exercise the Option may be
                  given, being not later than the day immediately  preceding the
                  tenth anniversary of the Date of Grant.


2.10     Subject to Rules 5.4 and 5.5.  each Option shall be granted so that its
         exercise  shall be  subject to the Option  Holder  continuing  to be an
         Eligible  Participant  throughout  the period between the Date of Grant
         and the date on which the Option is  exercised in  accordance  with the
         Rules.


2.11     An  Option  shall  be  personal  to the  Option  Holder  and may not be
         transferred,  assigned,  charged,  pledged or otherwise  disposed of or
         dealt (other than its exercise in accordance  with the Rules) with. Any
         purported  transfer,  assignment,  charge,  pledge or other disposal or
         dealing (other than its exercise in accordance with the Rules) with the
         Option  shall  cause the  Option  to lapse  forthwith  and each  Option
         certificate shall carry a statement to this effect.


3.       SCHEME LIMITS


3.1      No Option, other than a Founder Option, shall be granted if immediately
         following  such  grant it would  cause the  aggregate  of the number of
         Shares  which  have been or remain  to be  issued  on the  exercise  of
         Options granted under the Scheme,  excluding  Founder Options,  and the
         number of shares of the Company  which have been or remain to be issued
         pursuant to rights  granted under any other Company Share Scheme in the
         preceding 10 years but  excluding  any rights  granted under the Option
         Agreement  and any  shares  that have been  issued  before  the Date of
         Adoption  upon the exercise of rights  granted  under any other Company
         Share  Scheme,  to exceed  such  number of  shares  as  represents  the
         aggregate of 10 per cent of the issued  ordinary  share  capital of the
         Company immediately prior to the Date of Grant plus 1,550,000 Shares.


3.2      No Option, other than a Founder Option, shall be granted if immediately
         following  such  grant it would  cause the  aggregate  of the number of
         Shares  which  have been or remain  to be  issued  on the  exercise  of
         Options granted under the Scheme,  excluding  Founder Options,  and the
         number of shares of the Company  which have been or remain to be issued
         pursuant to rights  granted in the  preceding  10 years under any other
         share option scheme (other than a savings  related share option scheme)
         but  excluding any rights  granted  under the Option  Agreement and any
         shares  that have been  issued  before  the Date of  Adoption  upon the
         exercise of rights  granted  under any other share option scheme (other
         than any savings related share option scheme), to exceed such number of
         shares  as  represents  the  aggregate  of 7.5 per  cent of the  issued
         ordinary share capital of the Company  immediately prior to the Date of
         Grant plus 1,550,000 Shares.


3.3      The  aggregate  number of Shares  that may be the  subject  of  Founder
         Options  granted  under the  Scheme and any  rights  granted  under the
         Option Agreement shall not exceed 13,000,000 Shares.


3.4      For the  avoidance  of  doubt,  where  an  Option  lapses  or has  been
         renounced in accordance with the Rules,  the number of Shares comprised
         in that Option  immediately  before its lapse or renunciation  shall be
         disregarded for the purposes of this Rule 3.


4.       PERSONAL LIMITS


4.1      Save in the case of a Founder  Option  but  subject  to Rule  4.2,  the
         number of  Shares  in  respect  of which an  Option  is  granted  to an
         Eligible Participant shall be limited, and the Option shall take effect
         so and to the extent that the  aggregate  Market Value of the Shares he
         may acquire  pursuant to the  exercise of that Option when added to the
         aggregate  Market  Value  of the  Shares  Comprised  in the  Subsisting
         Options  previously granted under the Scheme (which for the purposes of
         this Rule 4.1 shall  also  include  cancelled  Options)  to him and the
         aggregate  market value of Shares he may acquire  pursuant to any other
         unexercised rights obtained under any other Company Share Scheme (other
         than a savings  related share option scheme or a profit sharing scheme)
         shall  not  exceed  or   further   exceed   four  times  the   Eligible
         Participant's  Total Remuneration for the Year of Assessment current at
         the Date of Grant or, if the Eligible  Participant  was not an Eligible
         Participant at the beginning of that Year of Assessment, four times the
         Eligible  Participant's  Total  Remuneration  for the  period of twelve
         months  beginning  with the first day during that Year of Assessment on
         which he became an Eligible Participant.


4.2      The  number of shares in respect  of which an  Exceptional  Performance
         Option is granted to an Eligible  Participant shall be limited, and the
         Exceptional  Performance  Option shall take effect so and to the extent
         that the aggregate  Market Value of the Shares he may acquire  pursuant
         to the exercise of that  Exceptional  Performance  Option when added to
         the aggregate  Market Value of the Shares  Comprised in the  Subsisting
         Options  previously granted under the Scheme (which for the purposes of
         this Rule 4.1 shall  also  include  cancelled  Options)  to him and the
         aggregate  market value of Shares he may acquire  pursuant to any other
         unexercised rights obtained under any other Company Share Scheme (other
         than a savings  related share option scheme or a profit sharing scheme)
         shall  not  exceed  or  further   exceed   eight  times  the   Eligible
         Participant's  Total Remuneration for the Year of Assessment current at
         the Date of Grant or, if the Eligible  Participant  was not an Eligible
         Participant  at the beginning of that Year of  Assessment,  eight times
         the Eligible  Participant's Total Remuneration for the period of twelve
         months  beginning  with the first day during that Year of Assessment on
         which he became an Eligible Participant.


4.3      For the  purposes of this Rule 4 market  value of Shares  shall mean in
         the case of rights granted under other Company Share Schemes the market
         value of the shares  subject to such rights at the time of the grant of
         the right as calculated  in  accordance  with the rules of the relevant
         Company Share Scheme.


4.4      For the  avoidance  of  doubt,  where  an  Option  lapses  or has  been
         renounced in accordance with the Rules,  the number of Shares comprised
         in that Option  immediately  before its lapse or renunciation  shall be
         disregarded for the purposes of this Rule 4.


5.       EXERCISE AND LAPSE OF OPTIONS


5.1      Subject  to this  Rule 5 and  Rules 6 and 8 an  Option  (other  than an
         Exceptional  Performance  Option)  may be  exercised  at any time on or
         after the third  anniversary  and before the tenth  anniversary  of its
         Date of Grant and an Exceptional Performance Option may be exercised at
         any time on or  after  the  fifth  anniversary  and  before  the  tenth
         anniversary of its Date of Grant.


5.2      An Option shall not be exercisable on or after the tenth anniversary of
         its  Date  of  Grant  under  any  circumstances  whatsoever  and  every
         Subsisting  Option shall lapse on the tenth  anniversary of its Date of
         Grant.


5.3      The right to exercise an Option shall  terminate  immediately  upon the
         Option Holder ceasing to be an Eligible  Participant except where Rules
         5.4 or 5.5 apply .


5.4      Subject  to  Rule  5.2  where  an  Option   Holder  dies  his  personal
         representatives may exercise any unexercised Options held by him within
         12 months of the date of death.


5.5      Where an Option Holder ceases to be an Eligible Participant:


         5.5.1    by reason of:


                  5.5.1.1     injury, disability or pregnancy; or


                  5.5.1.2     redundancy;


                  5.5.1.3     retirement on or after the Expected Retirement
                              Date;


                  5.5.1.4     the  company  by  which  the  Option   Holder  is
                              employed   ceasing  to  be  a
                              Participating Company; or


                  5.5.1.5     the transfer of the  business in which the Option
                              Holder is employed to a person
                              other than a Participating Company; or


         5.5.2    where the  circumstances are not as described in Rules 5.5.1.1
                  to 5.5.1.5  and the  Remuneration  Committee  in its  absolute
                  discretion  decides  not later  than 30 days after the date on
                  which the Option Holder  ceases to be an Eligible  Participant
                  to allow that Option Holder to exercise any Subsisting  Option
                  then held by him


         any Subsisting Option may be exercised no later than 6 months after the
         date of such  cessation  and for the purposes of this Rule 5.5 a female
         Option Holder shall not cease to be an Eligible  Participant  if absent
         from work because of  pregnancy  until and upon such time as she ceases
         to be entitled to exercise her right to return to work.


5.6      Save where  Rules  5.4,  5.5 or,  except in the case of an  Exceptional
         Performance  Option,  Rule 6 apply the  exercise of any Option shall be
         conditional  upon  the  relevant  Performance  Conditions  having  been
         fulfilled to the satisfaction of the  Remuneration  Committee or in the
         case of a Founder Option, subject to the conditions of Rule 2.2.


5.7      The Company shall notify each Option Holder in writing on each occasion
         that the accounts of the Company are distributed to its shareholders as
         to whether or not the  Performance  Conditions  have been  satisfied in
         respect of the then  immediately  preceding 3, or as appropriate 5 year
         period.


5.8      An Option shall lapse upon the earliest  occurrence of any of the
         following  events  insofar as it has not been exercised:


         5.8.1    the tenth anniversary of the Date of Grant;


         5.8.2    the first anniversary of the Option Holder's death;


         5.8.3    the expiry of 6 months from the date on which an Option Holder
                  ceases to be an Eligible Participant where Rule 5.5 applies;


         5.8.4    the earliest date upon which the Option is expressed to lapse
                  under Rule 6;


         5.8.5    the date of an event specified in Rule 2.11; or


         5.8.6    the Option Holder being adjudicated bankrupt.


6.       TAKEOVERS AND LIQUIDATIONS


6.1      If any person obtains Control of the Company as a result of making a
         general offer:


         6.1.1    to acquire the whole of the issued  ordinary  share capital of
                  the Company  which is made on a  condition  such that if it is
                  satisfied the person making the offer will have Control of the
                  Company; or


         6.1.2    to acquire all the shares in the Company which are of the same
                  class as the Shares


         then subject to the remaining  provisions of this Rule 6 any Subsisting
         Option may be exercised within the Appropriate Period and to the extent
         that it has not been exercised by the end of the Appropriate Period the
         Option shall lapse immediately upon the end of the Appropriate Period.
6.2      In the event that notice is given to the shareholders of the Company of
         a resolution to approve (subject to sanction by the Court) a compromise
         or  arrangement  proposed for the purposes of or in  connection  with a
         scheme for the  reconstruction  of the Company or its amalgamation with
         any other company or companies pursuant to Section 425 of the Act ("the
         Reconstruction  Scheme")  then any Option  Holder  may serve  notice to
         exercise  his  Subsisting  Options at any time  during the  Appropriate
         Period and to the extent that an Option has not been  exercised  by the
         end of the Appropriate  Period it shall lapse  immediately upon the end
         of the Appropriate Period.


6.3      If any  person  becomes  bound or  entitled  to  acquire  Shares in the
         Company  under  Sections  428 to 430F of the Act  then  any  Subsisting
         Option may be exercised at any time during the  Appropriate  Period and
         to the  extent  that  it  has  not  been  exercised  by the  end of the
         Appropriate  Period the Option shall lapse  immediately upon the end of
         the Appropriate Period.


6.4      If as a result of the  events  specified  in Rules 6.1 or 6.2 a company
         has obtained Control of the Company or if a company has become bound or
         entitled as mentioned in Rule 6.3 the Board shall seek the agreement of
         that other  company  ("the  Acquiring  Company") or a company which has
         Control over the  Acquiring  Company and if such  agreement is obtained
         each  unexercised  Option  ("Old  Option")  may within the  Appropriate
         Period  applicable to the relevant Rule be released in consideration of
         the grant of a new  Option  ("New  Option")  to  acquire  shares in the
         Acquiring  Company  or a company  which has  Control  of the  Acquiring
         Company which satisfies the following conditions:


         6.4.1    it is a right to acquire  such number of such shares as has on
                  acquisition of the New Option an aggregate  Market Value equal
                  to the aggregate Market Value of the Shares subject to the Old
                  Option on its disposal;


         6.4.2    it has a subscription  price per share such that the aggregate
                  price payable on complete  exercise equals the aggregate price
                  which would have been payable on complete  exercise of the Old
                  Option; and


         6.4.3    it is otherwise identical in terms to the Old Option.


         The New Option  shall for all other  purposes of this Scheme be treated
         as  having  been  acquired  at the  same  time  as the  Old  Option  in
         consideration  of the  release of which it is granted and where any New
         Options are granted pursuant to this Rule 6.4 Rules 5, 6,7, 8 and10 and
         all  definitions  in Rule 1 as  appropriate  in  those  Rules  shall in
         relation  to the New  Options  be  construed  as if  references  to the
         Company and to the Shares were  references  to the company  whose share
         capital  includes shares over which the New Option has been granted and
         to the shares in that company but references to a Participating Company
         shall  continue to be  construed as if  references  to the Company were
         references to Huntingdon  Life Sciences  Group plc. Where in accordance
         with this Rule 6.4 Old Options are released and New Options granted the
         New Options shall not be exercisable in accordance  with Rules 6.1, 6.2
         and 6.3 above by virtue of the event by reason of which the New Options
         were granted.


6.5      In the event that notice is given to the shareholders of the Company of
         a resolution to be proposed for the voluntary winding up of the Company
         any Option Holder may serve notice to exercise,  his Subsisting Options
         at any time up to the passing of the resolution  provided that any such
         notice to exercise shall only be effective if the resolution is passed.
         If such resolution is duly passed all Options shall, to the extent that
         they have not been exercised, lapse.


6.6      For the  purposes of this Rule 6 other than Rule 6.4 a person  shall be
         deemed to have obtained Control of a Company if he and others acting in
         concert with him have together obtained Control of it.


6.7      The  exercise of an Option  pursuant to the  preceding  provisions  of
         this Rule 6 shall be subject to the provisions of Rule 8 below.


6.8      An Exceptional  Performance Option may not be exercised under this Rule
         6  unless  the  Performance  Conditions  applicable  to  it  have  been
         satisfied to the  satisfaction of the Remuneration  Committee  provided
         that the growth in Earnings  per Share  shall be  measured  between the
         Date of Grant of the Exceptional Performance Option and the date of the
         event by virtue of which the  Exceptional  Performance  Option  becomes
         exercisable  under  this Rule 6 and the last  Earnings  per Share  that
         shall be used for that purpose  shall be the Earnings per Share for the
         Accounting  Period  current  at the date of the said event by virtue of
         which  the  Exceptional   Performance  Option  becomes  exercisable  as
         determined  by the  Remuneration  Committee  in  consultation  with the
         Auditors or such other advisers selected by the Remuneration  Committee
         in its absolute discretion.


7.       VARIATION OF SHARE CAPITAL


         In the event of any  variation  in the share  capital of the Company by
         way of capitalization or rights issue or any consolidation sub-division
         or  reduction  of capital or  otherwise  by the  Company  the number of
         Shares  subject to any Option  and the  Subscription  Price for each of
         those Shares shall be adjusted by the  Remuneration  Committee  subject
         (except in the case of a capitalization) to written confirmation by the
         Auditors that in their opinion such  adjustment is fair and  reasonable
         provided that:


         7.1      the aggregate amount payable on the exercise of an Option in
                  full is not increased; and


         7.2      the Subscription Price for a Share is not reduced below its
                  nominal value.


8.       MANNER OF EXERCISE OF OPTIONS


8.1      No Option shall be exercisable save in accordance with the then current
         Model Code for Securities Transactions by Directors of Listed Companies
         issued by the London Stock Exchange.


8.2      Subject  to the  provisions  of Rule 5 and this Rule 8 an Option may be
         exercised  at  any  time  in  whole  or in  part  but  not  unless  the
         Remuneration Committee otherwise permits in respect of less than 10 per
         cent of the  Shares the  subject of the  original  Option  unless  such
         smaller percentage represents all the remaining Shares under the Option
         by  the   Option   Holder  or  (as  the  case  may  be)  his   personal
         representatives   giving  a  notice   of   exercise   to  the   Company
         substantially  in the form set out in  Schedule  3  accompanied  by the
         appropriate  payment and the relevant  Option  certificate and shall be
         effective on the date of its receipt by the Company  ("exercise  date")
         provided that wherever relevant the Performance  Conditions shall first
         have been fulfilled to the satisfaction of the Remuneration Committee.


8.3      No Option shall be capable of being quoted or dealt in on any stock
         exchange.


8.4      Subject  to Rules  9.2 and 9.3  Shares  shall be  allotted  and  issued
         pursuant to a notice of exercise  within 42 days of the  exercise  date
         (or such date  which is the later of the date on which (a) the  payment
         referred to in Rule 9.2 is receiving the relevant company;  and (b) the
         Board  is  satisfied  that the  sale  referred  to in Rule 9.3 has been
         completed.  Save  for any  rights  determined  by  reference  to a date
         preceding the date of allotment  such Shares shall rank pari passu with
         the other  shares of the same  class in issue at the date of  allotment
         and  will  be  subject  to  all  the  provisions  of  the  Articles  of
         Association of the Company relating to voting,  dividends,  transfer or
         otherwise.


8.5      When an Option  is  exercised  only in part the  balance  shall  remain
         exercisable on the same terms as originally applied to the whole Option
         and a new Option  certificate  representing the balance shall be issued
         by the Company as soon as possible after the partial exercise.


8.6      Where relevant, within 28 days after Shares have been allotted pursuant
         the  exercise of an Option the Company  shall make  application  to the
         Council of the London Stock  Exchange for the admission to the Official
         List of the Shares allotted and issued following such exercise.


8.7      It shall be a  condition  of  participation  in the Scheme  that in the
         event of an Option Holder  ceasing to be an Eligible  Participant  (for
         whatever   reason)  he  shall  not  be  entitled  to  any  compensation
         whatsoever  by reason of any  termination  or  alteration  of rights or
         expectations  under the Scheme whether such  compensation is claimed by
         way of damages for wrongful dismissal or breach of contract or for loss
         of office or otherwise  howsoever.  Participation  in this Scheme by an
         Option Holder is a matter  entirely  separate from any pension right or
         entitlement  he may have and from his terms or conditions of employment
         and  participation in this Scheme shall in no respects  whatever affect
         in any way an Option Holder's pension rights or entitlement or terms or
         conditions of employment.


9.       TAXATION


9.1      If a Tax Liability  arises in respect of an Option the Company shall be
         entitled to deduct to the extent  permitted by law such  amount(s) from
         any payment due to be made by the Company or any company which controls
         or is  controlled  by the Company to or in respect of the Option Holder
         in  respect of that  Option  during  the same  calendar  month or other
         relevant  period in which the event  occurs  and/ or in any  subsequent
         calendar  month  or such  relevant  period  in  order  to  satisfy  and
         discharge the Tax Liability whether or not such payment is of an income
         or capital nature.


9.2      If and to the extent the Tax  Liability  referred  to in Rule 9.1 is of
         income tax which  exceeds the amount from which  deductions  in respect
         thereof  can be made  in any  one  period  referred  to in Rule  9.1 in
         respect of the Option Holder concerned, that Option Holder shall pay or
         reimburse  the Company for the amount of the excess on demand or within
         such  period as may be  specified  in any written  notice  given by the
         Company  and the  Company  shall not be  obliged to issue and allot any
         Shares  upon the  exercise  of an  Option  until it has  received  such
         payment.


9.3      Where a Tax  Liability  arises in respect of the exercise of an Option,
         the Board may, without prejudice to the Company's rights under Rule 9.1
         and Rule 9.2, by written notice to the Option Holder concerned nominate
         as his bare trustee any person (the "Bare Trustee") to sell such number
         of Shares  issued upon the exercise of the Option as may be required in
         order to discharge the Tax Liability and any other liability (including
         costs)  connected  with the said sale and the Bare Trustee shall pay an
         amount  equal  to the  Tax  Liability  to  the  Company  and  otherwise
         discharge any other said  liability to the extent that the net proceeds
         from the said sale  permit.  The Company  shall not be obliged to issue
         and allot any Shares upon the exercise of an option until the said sale
         has been completed to the satisfaction of the Board.


10.      ADMINISTRATION AMENDMENT AND TERMINATION


10.1     The Scheme shall be  administered by the Remuneration  Committee whose
         decision on all disputes shall be final.


10.2     The Board may from time to time make amendments to these Rules
         provided that:


         10.2.1     no  amendment  may   detrimentally   affect  an  Option
                    Holder  as  regards  any Subsisting  Option  held by him on
                    the date of the  amendment  being made  except
                    with the  consent in writing of (a) in the case of a Founder
                    Option,  the holder of that  Founder  Option and (b) in
                    every  other case such  Option  Holders  who,
                    assuming they exercise their Options in full,  would thereby
                    become  entitled to not less than three  quarters  in
                    nominal  amount of all the Shares  which  would
                    fall to be allotted upon exercise in full of all Subsisting
                    Options; and


         10.2.2     except  with the  prior  sanction  of the  Company  in
                    general  meeting  no such modification  or  variation shall
                    extend the class of person  eligible  for the grant  of
                    Options  or alter to the  advantage  of  Option  Holders
                    (present  or future) Rules 2.1, 2.2, 2.3, 2.7,  2.10, 3, 4,
                    or 7 the  definitions of "Eligible Participant",
                    "Participating  Company" or "Subscription  Price" except
                    for minor amendments to benefit the  administration  of the
                    Scheme,  to comply with or take account of any proposed or
                    existing  legislation  or law or to obtain or maintain
                    favourable  tax,  exchange  control or regulatory treatment
                    for Option  Holders (present or future) or for any
                    Participating Company; and


         10.2.3     written  notice of any  alteration  made in accordance with
                    this Rule 10.2 shall be given to all Option Holders.


10.3     The cost of establishing and operating the Scheme shall be borne by the
         Participating   Companies  in  such  proportions  as  the  Board  shall
         determine.


10.4     The Company in general  meeting or the Board may at any time resolve to
         terminate  this  Scheme  in which  event no  further  Options  shall be
         granted but the  provisions  of this Scheme shall  continue in force in
         relation to Subsisting Options.


10.5     The Company shall at all times keep available sufficient authorised and
         unissued  Shares to  satisfy  the  exercise  to the full  extent  still
         possible  of all  Options  which  have  neither  lapsed  nor been fully
         exercised  taking  account of any other  obligations  of the Company to
         issue unissued Shares.


10.6     Any  notice to be given  pursuant  to the terms of these  Rules must be
         given in  writing to the party due to  receive  such  notice at (in the
         case of the Company) its registered office from time to time or (in the
         case of an individual) his address as notified to the Company from time
         to time.  Notice must be  delivered  personally  or sent by first class
         pre-paid recorded delivery or registered post (air mail if overseas) or
         by facsimile  transmission  and shall be deemed to be given in the case
         of delivery  on delivery  and in the case of posting (in the absence of
         evidence of earlier  receipt)  within 48 hours after posting (6 days if
         sent  by air  mail)  and in  the  case  of  facsimile  transmission  on
         completion of transmission.


<PAGE>

                                   SCHEDULE 1


                                 Letter of Grant


                           [The Company's Letterhead]


                                                              Date


To:       Eligible Participant


Dear  [name of Eligible Participant]


THE HUNTINGDON LIFE SCIENCES GROUP UNAPPROVED SHARE OPTION SCHEME ("the Scheme")


1        The  Directors  have granted you  [an/four]  option[s]  [designated  as
         ['A'/'B'/'C'/'D']  Option[s] [respectively] [an Exceptional Performance
         Option]] over [ ] ordinary  shares [each]  ("Shares") in the capital of
         Huntingdon Life Sciences Group plc ("the Company") under and subject to
         the rules of the Scheme ("the  Option")  which was approved and adopted
         by a written  resolution  of the  shareholders  of the Company on 199 .
         [Each of your  options  is a Founder  Option  for the  purposes  of the
         Rules.] A copy of the rules of the Scheme is enclosed herewith.


2        The subscription  price per Share payable on the exercise of the Option
         is [12.5]/[]p.  This subscription  price is subject to adjustment under
         Rule 7 of the  Scheme if the  Company's  share  capital  is  altered or
         re-organised, in specified ways.


3        An Option certificate for[each of] your Option[s] is enclosed herewith.


4        Under  the  rules  of the  Scheme  ("the  rules"),  except  in  certain
         circumstances   the  Option   may  not  be   exercised   earlier   than
         [three]/[five] years from the Date of Grant.


5        [The  Option may not be  exercised  unless the  Performance  Conditions
         attached to this letter have been fulfilled to the  satisfaction of the
         Remuneration Committee except in certain circumstances permitted by the
         rules.][Your  Founder  Option  may not be  exercised  unless the Market
         Value of the Shares is equal to or exceeds the  relevant  target  price
         specified in the relevant option certificate.  You should refer to Rule
         2.2 in connection with this.]


6        The Option shall not be  exercisable  save in accordance  with the then
         current  Model Code for  Security  Transactions  by Directors of Listed
         Companies issued by the London Stock Exchange.


7        You may  renounce  the  Option in whole or in part by  signing  (in the
         presence of a witness)  and  returning  this letter  together  with the
         enclosed  Option  certificate to me before [date 21 days after the Date
         of Grant].


Yours faithfully,


 .....................


Secretary


[NOTE:   Performance Conditions must be attached to this letter]


                                  RENUNCIATION


I  [PRINT  NAME]  hereby  renounce  the  [Exceptional  Performance]  Option  [in
whole]/[in  respect of Shares].  I am returning with this letter the certificate
in respect of the [Exceptional Performance] Option referred to above.


SIGNED as a DEED by
------      ----


[NAME]
 ----


in the presence of:


Signature:


Name:


Address:


Occupation:




<PAGE>


                                   SCHEDULE 2
                           Option Certificate Number:
 -------------------------------------------------------------------------------
                      Incorporated under the Companies Acts

                Registered in England and Wales under Number [ ]

                    TOTAL NUMBER OF ORDINARY SHARES OF p EACH

          INCLUDED IN THIS ['A'/'B'/'C'/'D']/[EXCEPTIONAL PERFORMANCE]
                                 OPTION (number)
 -------------------------------------------------------------------------------
This is to certify that (name) was granted an  ['A'/'B'/'C'/'D']  Option  [which
was designated as an Exceptional  Performance Option] on the day of to subscribe
for ordinary  shares of [ ]p each in the capital of the Company  ("Shares") at a
Subscription  Price of [12.5P]/[  ]per Share  giving an  aggregate  Subscription
Price of (pound) upon the terms of the Huntingdon Life Sciences Group Unapproved
Share Option Scheme ("the scheme") ("the  Option").  The Option may be exercised
only at the times and in the  circumstances and manner permitted by the rules of
the Scheme and cannot be transferred,  assigned,  charged,  pledged or otherwise
disposed of or dealt with (other than its exercise in accordance with the Rules)
with. Any purported transfer,  assignment,  charge,  pledge or other disposal or
dealing (other than its exercise in accordance  with the Rules) with shall cause
the Option to lapse forthwith.


[This  ['A'/'B'/'C'/'D']  Option is subject to the conditions  specified in Rule
2.2 and cannot be  exercised  until the  Market  Value of a Share is equal to or
more than 25/50/75/100 pence.]


THE COMMON SEAL of
HUNTINGDON LIFE
SCIENCES GROUP plc
was affixed to this deed
in the presence of:
                                    Director

                                    Secretary


Date .........................


NOTE:



(1)  A form of exercise of the Option is printed  overleaf.  This  certificate
     must be surrendered on the exercise, in whole or in part, of the Option.



(2)  The number  and/or  description  of shares  covered by this  Option and/or
     the  Subscription Price may be varied in accordance with the Rules of the
     Scheme.



(3)  Notice to  exercise  this  Option  must be given by [date no later  than
     the day  before  the tenth anniversary of the Date of Grant].



(4)  The  right  to  exercise  this  Option  shall  be  subject  to the  due
     satisfaction of the Performance Conditions specified on the attached sheet.


<PAGE>

                                   SCHEDULE 3
                                Form of Exercise
                (TO BE PRINTED ON REVERSE OF OPTION CERTIFICATE)
                 PLEASE READ THE NOTES AT THE FOOT OF THIS FORM
                         CAREFULLY BEFORE COMPLETING IT

The Secretary
Huntingdon Life Sciences Group plc


I,  the  undersigned,  having  become  entitled  so to do  hereby  exercise  the
['A'/'B'/'C'/'D']  [Exceptional  Performance]  Option referred to overleaf ("the
Option")  in respect  of Shares  comprised  in the Option  upon the terms of the
Huntingdon Life Sciences Group Unapproved Share Option Scheme ("the Scheme") and
agree to accept the Shares to be  allotted  and issued  pursuant to this Form of
Exercise  subject to and in  accordance  with the  Memorandum  and  Articles  of
Association  of the  Company  and  hereby  request  you to  place my name on the
Register of Members in respect thereof.

I enclose a  remittance  for  (pound)  being the  aggregate  Subscription  Price
payable  for the Shares in respect of which the Option is now  exercised  at the
Subscription Price per Share specified overleaf.

For the  avoidance  of  doubt,  I hereby  agree  that Rule 9 of the rules of the
Scheme  may be  applied  by the  Company  and the Board at their  discretion  in
respect of the Option hereby exercised.

If applicable,  I hereby request you to despatch a balance  certificate  for the
Option to subscribe for any Shares  included in the Option  referred to overleaf
and not exercised on this occasion,  by post at my risk to the address mentioned
below.


Signature ...................................

Surname .....................................

Forename(s) .................................

Address .....................................

 .............................................


Note:



(1)      Although  the Option  referred  to  overleaf  is personal to the holder
         named  overleaf  it may be  exercised  (subject  to  Rule  5.6)  by his
         personal  representative(s)  if he dies  while it is still  capable  of
         exercise provided the personal  representative(s) does/do so before the
         expiration of twelve months from the date of the holder's  death or ten
         years  from the date of its grant (if  sooner).  If there are more than
         one, each of the personal representatives must sign this form.

(2)      Options must be exercised in respect of whole numbers of Shares. Please
         indicate the number of Shares you wish to  subscribe  on this  occasion
         which must not exceed the number of Shares comprised in the Option.  In
         any event you will be deemed to have  exercised  your rights in respect
         of that whole number of Shares which can be subscribed  with the moneys
         represented by your remittance.

(3)      The  remittance  should  be  for  an  amount  equal  to  the  aggregate
         Subscription  Price,  being the  Subscription  Price  per  Share  shown
         overleaf, multiplied by the number of Shares applied for.

(4)      Please  note that  before  any  Shares  are  allotted  to you,  any tax
         liability that arises on the exercise of your Option may be required to
         be satisfied by the Board.