Deed of Variation



between

Huntingdon Life Sciences Limited
as the Company


and


Huntingdon Life Sciences Group plc



and


Christopher Cliffe
as the Director


<PAGE>



THIS DEED is dated the 7th day of  August 1998 and made

BETWEEN:

(1)      Hungtindon Life Sciences Limited ("the Company"), registered in England
         and Wales and having its registered  office at Wooley Road,  Alconbury,
         Huntingdon, Cambs PE17 5HS;

(2)      Huntingdon  Life Sciences Group plc ("HSLG plc")  registered in England
         and Wales and having its registered  office at Wooley Road,  Alconbury,
         Huntingdon, Cambs PE17 5HS; and

(3) Christopher  Cliffe ("the Director") of Delamere,  Cutler's Green,  Thaxted,
Dunmow, Essex CM6 2PZ.

BACKGROUND 

The  Director is  currently  employed  by the Company and is entering  into this
Agreement to vary his existing service  agreement with the Company such that his
employment  with the Company  will  terminate  by mutual  consent on 31 December
1998.  For the  avoidance  of doubt,  in  respect  of matters to which this Deed
relates it will supersede his existing  terms and conditions of employment,  but
otherwise the existing terms and conditions will remain unchanged.

For the mutual  considerations  contained  in this  Agreement  and the  attached
compromise agreement taken together THE PARTIES AGREE THAT:

1.       This  agreement is expressly  conditional on the completion of the cash
         subscription  and open  offer for new  shares in HLSG plc in  September
         1998.

2.       Unless the context  otherwise  requires in this Agreement the following
         words and phrases have the following meanings given below:

(A)       "Associated  Company" means any holding company (as defined in
          section 736 of the  Companies Act 1985) of the Company and any
          company of which the Company, any such holding company, or any
          subsidiary  (as  defined in section 736 of the  Companies  Act
          1985) of the  Company or any such  holding  company,  holds or
          controls  more than 20% in nominal  value of the equity  share
          capital;

(B)       "Group"  means the  Company  and any  Associated  Company  and
          "Group Company' shall be construed accordingly; and

(C)       :Service  Contract"  means the contract of employment  entered
          into by the Director  and the Company  dated 15 March 1993 (as
          amended on 31 May 1994,  05 October 1994, 10 March 1995 and 05
          March 1997);

3.       It is  hereby  agreed  that the  employment  of the  Director  with the
         Company will  terminate on 31 December 1998 with  immediate  effect and
         without any notice or further  payment  (save as specified  below) from
         the Company or any Group Company. The Director will continue to receive
         his salary and other contractual benefits until that date.

4.       It is agreed that,  whilst the Director will remain in employment until
         31 December  1998,  the Company may, at its  discretion,  assign to the
         Director some or none of the duties under his Service  Contract and may
         require the Director not to attend at the  Company's  premises for some
         or none of the period.  Such  instructions  from the Company  shall not
         constitute a breach of the Service Contract.

5.       The Company agrees to give further  consideration  to ways in which the
         Director   will  be  given   financial   incentives   to  maximize  the
         profitability  of the Company and/or any Group Company and the value of
         its assets during the period until the termination of his employment.

6.       As soon as is reasonably  practicable and, in any event, within 14 days
         of the  termination  of employment of the Director on the date referred
         to in  paragraph 3 above,  both  parties  will enter into a  comprising
         agreement  in the  form  attached  hereto.  Under  the  terms  of  that
         agreement   The  Company   will  pay  to  the   Director   the  sum  of
         (pound)250,000  )less such tax and  national  insurance  as is properly
         deductible therefrom) which the parties acknowledge is in consideration
         for the variation in the rights of the Director  under the terms of the
         Service Contract and loss of employment.

7.       The  Director  hereby  confirms  that  he has,  as at the  date of this
         Agreement,  taken  independent  legal  advice  on the  implications  of
         signing a compromise agreement in the attached form.

8.       It is hereby agreed that all provisions in the Service  Agreement,  the
         agreement  between the Director and HLSG plc dated 31 May 1994, and the
         agreement made between the Company,  the Director and HLSG plc dated 10
         March 1995  relating to payments to the Director on a change of control
         are hereby deleted with immediate effect.

9.       The Director will, immediately upon termination of his employment, sign
         and date a letter  resigning all  directorships he holds in the Company
         or any Group Company with immediate effect in the form attached hereto.
         Should  the  Director  fail to do so within  seven  days of the date of
         termination of employment the Company is hereby irrevocably  authorised
         to  appoint  a person  in his name and on his  behalf  to  execute  any
         documents and to do all things requisite to give effect thereto.

10.      The Company  agrees that it will consult with the Director prior to any
         announcement  being made within the Group or externally  concerning the
         termination of his employment.

11.      The  Director  acknowledges  that he has not and will not  receive  any
         payment from the Company or any Group Company in respect of his loss of
         office as director of the Company or any Group Company as  contemplated
         by paragraph 9 above.

12.  This Deed shall be  governed  by and  interpreted  in  accordance  with the
English Law.

IN WITNESS whereof this Deed has been entered into the day and year first before
written.

SIGNED by                           (Director)       )
and                                 (Secretary)      )
and thereby executed by HUNTINGDON                   )
LIFE SCIENCES LIMITED                                )
as its Deed                                          )



SIGNED by                           (Director)       )
and                                 (Secretary)      )
and thereby executed by HUNTINGDON                   )
LIFE SCIENCES GROUP PLC                              )
as its Deed                                          )



SIGNED AS A DEED AND DELIVERED                       )
By the said CHRISTOPHER FREDERICK                    )
CLIFFE                                               )
In the presence of



Name:

Address:

Occupation:


<PAGE>


                                WITHOUT PREJUDICE
                               SUBJECT TO CONTRACT


DRAFT COMPROMISE AGREEMENT

This Agreement is made the [insert date of completion]  between  Huntingdon Life
Sciences Limited (the "Company") and Christopher Cliffe ("the Employee").

1.       Following the  termination  of the  employment of the Employee with the
         Company on 31  December  1998 the  Company  will  within 14 days of the
         later  of (a)  the  date  of this  Agreement;  and  (b) the  Employee's
         compliance  with  paragraph  3  below  pay to the  Employee  the sum of
         (pound)250,000  (less such income tax and national  insurance if any as
         the Company is obliged by law to deduct and less any  outstanding  sums
         owed by the  Employee to the Company for example by way of loan) by way
         of compensation for loss of employment.

2.       The Employee  hereby agrees to be  responsible of the payment of any
         tax in respect of the sum payable under  paragraph 1 (other than for
         the avoidance of doubt,  any tax withheld by the Company in paying
         the sum to the  Employee)  and the  Employee  hereby  agrees to
         indemnify  the  Company and any other company in the group of
         companies  of which the Company is a member  ("group  Company") and
         keep the Company and all other Group  Companies  indemnified on a
         continuing  basis against any claim or demand which is made  against
         the Company  and/or any Group  Company in  respect of any liability of
         the Company  and/or  any Group  Company to deduct an amount if tax or
         an amount in respect of tax from the payment  made  under this
         Agreement, including any interest or penalties imposed in connection
         therewith  and  including,  but without  prejudice to the  generality
         of the  foregoing,  any claim or demand made in respect of United
         Kingdom Income Tax or PAYE.

3.       Before  payment under  paragraph 1 is made the Employee shall return to
         the Company any remaining  property  belonging to the Company which has
         been  in his  possession  or  under  his  control,  including  (without
         limitation)  the  facsimile  machine,  credit  card,  keys,  and  other
         documents  (whether  confidential  or not) or any other property in his
         possession  or under his control by reason of his  employment  with the
         Company (and any copies of any of the  foregoing) and the Company shall
         not unreasonably  withhold its confirmation  that all such property has
         been returned.

4.       The  arrangements  et out in this  Agreement  are in full and final
         settlement  of all or any claims,  costs,  expenses or rights of
         action of any kind  whatsoever  or howsoever arising (whether arising
         under  common law,  statute or  otherwise  and whether  arising in the
         United  Kingdom or in any other country in the world and  including, 
         but not limited  to,  any claims  under the Equal Pay Act 1970, Sex 
         Discrimination   Act   1975,Race   Relations  Act  1976,   Trade Union
         and  Labour   Relations (Consolidation)  Act 1992,  Employment Rights
         Act  1996,  Disability  Discrimination  Act 1995 or in respect  of
         which a Conciliation Officer is authorised  to act or any  claims
         arising  under  any directive or other  legislation  applicable  in
         the United  Kingdom by virtue of the United  Kingdom's membership  of
         the  European Union which the Employee has or may have  against the
         Company or any Group  Company or against any  employee,  agent or
         office of the Company or Group  Company and whether arising  directly
         or indirectly  out of or in connection  with the  Employee's  contract
         of employment with the Company and any collateral contracts with any
         Group Company, their termination or otherwise.

5.       The Employee hereby confirms that he continues to be bound by the terms
         of the restrictions contained in clause 9 of his contract of employment
         with the Company.

6.       The Employee acknowledges that by reason of his continuing  obligations
         of confidentiality he is obliged to keep the circumstances  surrounding
         the  termination  of his  employment  and the  terms of this  Agreement
         confidential,  but that nothing in this Agreement  shall prevent either
         party  from   disclosing   information   as  required  by  law  or  any
         self-regulatory organisation or in order to take professional advice or
         as ordered by a court of competent jurisdiction.

7.       The Employee  hereby  warrants that he has not at any time  committed a
         repudiatory  breach of his contract of  employment  which would entitle
         the Company to terminate his employment without notice.

8.       The  Employee  has  received  independent  advice from  [insert name of
         adviser] acting in [his/her] capacity as a qualified lawyer in the firm
         of [insert name of firm] who holds a current practising  certificate as
         to the terms and effect of this  Agreement and in particular its effect
         on the  ability  of  the  Employee  to  pursue  his  rights  before  an
         employment tribunal.  There was in force when [adviser] gave the advice
         referred to in this paragraph a contract of insurance,  or an indemnity
         provided for members of a profession or professional  body covering the
         risk  of a  claim  by the  Employee  in  respect  of  loss  arising  in
         consequence of this advice.

9.       This  Agreement  satisfies the  conditions  for  regulating  compromise
         agreements  under the Sex  Discrimination  Act 1975, Race Relations Act
         1976,  Trade Union and Labour Relations  (Consolidation)  Act 1992, the
         Employment Rights Act 1996 and the Disability Discrimination Act 1995.

10.      [Adviser] by signing this letter  confirms to the Company  that, to the
         best of  [his/her]  knowledge  and belief,  the  statements  set out in
         paragraphs 7 and 8 are correct.

11.      The  Employee  shall on the  date of his  signature  to this  Agreement
         resign as a director of the Company  and all other Group  Companies  in
         which he holds directorship in the form attached hereto.

This Agreement although marked "Without Prejudice" will upon signature by all of
the parties be treated as an open document  evidencing  an agreement  binding on
the parties.


Signed.......................................
         For and on behalf of the Company

Dated    .......................................





Signed.......................................
         The Employee

Dated    .......................................




Signed.......................................
         [Adviser]

Dated    .......................................




<PAGE>


To the Board of Directors
Huntingdon Life Sciences Group plc
Huntingdon Life Sciences Ltd
[insert names of other Group Companies in which directorships are held]








Dear Sirs

Huntingdon Life Sciences Group plc
Huntingdon Research Centre ltd
[insert names of other Group Companies in which directorships are held]


I hereby  resign  from the  office  of  Director  of the  above  companies  with
immediate  effect,  and I  acknowledge  and  confirm  that I have  no  claim  of
whatsoever  kind  outstanding for  compensation  or otherwise  against the above
companies,  their  servants,  officers,  agents or  employees  in respect of the
termination of my directorships.

Yours faithfully







SIGNED and DELIVERED as a DEED      )
By CHRISTOPHER FREDERICK            )
CLIFFE                              )
In the presence of                  )