THIS AGREEMENT is made the_______ day of__________July 1998

BETWEEN;

      (1) Bioenvision,  Inc. whose  registered  office is at Trafalgar House, 11
      Waterloo Place, London SW1Y 4AU (the 'Company') and

      (2) Thomas Nelson, of Castlefield, Old Park Lane, Farnham, Surrey, England
      (the 'Director').

      Whereas it is agreed that the Company  shall  employ the  Director and the
      Director  shall serve as a Director of the Company on the following  terms
      and subject to the following conditions:

1     DEFINITIONS AND INTERPRETATION

1.1   In this  agreement  unless the context  otherwise  requires the  following
      expressions shall have the following meanings:

"Board"           The Board of Directors for the time being of the Company

"Group"           The Company and its subsidiaries from time to time

"Incapacity"      Any illness or other like cause  incapacitating  the  Director
                  from attending to his duties

"Index            Where any  amount  is  stated  to be index  linked it shall be
linked"           adjusted  annually on 1 May each year commencing on 1 May 1998
                  by a percentage equal to the percentage increase in the retail
                  price index  published  by the  Government  to 30 April in the
                  year in question from the 30 April in the previous year

"Intellectual     Includes letters patent, trade marks, service marks,  designs,
 property"        utility models,  copyrights,  design rights,  applications for
                  registration  of any of the  foregoing  and the right to apply
                  for them in any part of the world;  moral rights,  inventions,
                  confidential information,  know-how, and rights of like nature
                  arising or  subsisting  anywhere in the world,  in relation to
                  all of the foregoing, whether registered or unregistered

"Subsidiary"      A subsidiary  (as defined by the  Companies  Act 1985) for the
                  time being of the Company

1.2 Any  reference  to a  statutory  provision  shall be  deemed  to  include  a
reference to any statutory modification or re-enactment of it.

1.3 The headings of this agreement are for convenience only and shall not affect
its construction or interpretation.


2     TERM OF EMPLOYMENT

The employment of the Director  (subject to termination as provided below) shall
be for an initial period of 2 years from _______ 1998 and shall be terminable by
either


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Agreement between Company and Director
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party giving to the other not less than 3 months  notice in writing  expiring at
any time after the expiry of such period.

3     DUTIES

3.1   The Director shall during his employment under this Agreement:

      3.1.1 perform the duties and  exercise the powers which the Board may from
            time to time  properly  assign to him in his capacity as Director of
            the Company or the  Director of any one or more of its  subsidiaries
            including  serving on the Board of such subsidiaries or on any other
            executive body or any committee of such a company, and

      3.1.2 do all that is  reasonably  in his  power to  promote,  develop  and
            extend the  business of the Company and of its  subsidiaries  and at
            all times and in all  respects  to conform  to and  comply  with the
            proper and reasonable directions and regulations of the Board.

3.2   During  any  notice  period the  Director  shall  carry out his duties and
      exercise his powers with any other directors appointed by the Board to act
      with him and the Board may at any time  during  such  period  require  the
      Director to cease performing or exercising any duties or powers.

3.3   The Director  shall work in any place within the United  Kingdom which the
      Board may require for the proper  performance  and  exercise of his duties
      and powers and he may be required to travel on the business of the Company
      or any of its subsidiaries anywhere in the world.

3.4   If the Company  requires the Director to work permanently at a place which
      necessitates  a move from his present  address the Company will  reimburse
      the Director for all removal expenses directly and reasonably  incurred as
      a result of the Company's  requirement up to the maximum  permitted  under
      the Inland Revenue's Extra Statutory concession from time to time relating
      to such reimbursement.

4     OFFICE OF DIRECTOR

During his employment under this Agreement the Director shall not:

4.1   voluntarily resign as Director of the Company.

4.2   voluntarily  do or  refrain  from  doing any act  whereby  the office as a
      director of the Company is or becomes liable to be vacated.

5     REMUNER4TION

5.1   Salary

      As remuneration, the Director shall be paid a basic salary (which shall be
      index linked) at the rate of $ (US dollars) per annum (or such higher rate
      as the Company may in its absolute  discretion from time to time decide or
      award)  inclusive of any director's fees payable to him under the Articles
      of Association of the Company and its subsidiaries,  payable in arrears by
      equal monthly instalments on the 25th day of every month.


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Agreement between Company and Director
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5.2   Bonus

      The  Director  shall  be  entitled  to an  annual  bonus  which  shall  be
      calculated as a percentage of the Director's  salary on the achievement by
      the  Company of its  Target as agreed.  The bonus may be paid as shares in
      the Company, at the Director's request.

6     PENSION SCHEME

The Director  shall during his  employment  under this  Agreement be entitled to
become a member of a  private  pension  plan  scheme  and in the event  that the
Director  shall  become  such a member of such a scheme the  Company  will pay a
contribution  equal to 5% of the Director's  Salary to the Scheme  provided that
the Director also pays a contribution equal to 3% of his salary to the scheme.

7     EXPENSES

The Company  shall by way of  reimbursement  pay, or procure to be paid,  to the
Director all reasonable  travelling hotel and other expenses wholly  exclusively
and necessarily  incurred by him in or about the performance of his duties under
the Agreement.

8     ILLNESS

8.1   The  Director  shall  continue  to be paid  during his  absence due to his
      incapacity  (such  payment to be  inclusive of any  statutory  sick pay or
      social security benefits to which he may be entitled) for a total of up to
      8 weeks in any one year.

8.2   After  the  expiry of the 8 week  period  referred  to in  clause  8.1 the
      Director shall  continue to be paid 50% of his basic salary  (inclusive of
      any  statutory  sick pay or social  security  benefits  to which he may be
      entitled) up to a further period of 4 weeks in any one year.

9     DEATH IN SERVICE

9.1   On the death of the  Director in service the  Director's  Estate  shall be
      entitled to receive a lump sum benefit equal to two times his basic salary
      at the previous May,  excluding any bonus  (hereinafter  the  "Pensionable
      Salary").

10    PERSONAL ACCIDENT

10.1  The  Director  is entitled  to become a member of the  Company's  Personal
      Accident Travel policy.


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11    DIRECTORS AND OFFICERS LIABILITY INSURANCE

The Director shall be entitled to become a member of the Company's Directors and
Officers Liability Insurance Scheme.

12    RESTRICTIONS DURING EMPLOYMENT

12.1  During the continuance of his employment under this Agreement the Director
      shall, unless prevented by incapacity, devote to the Company (or any other
      member of the group by whom he is employed) his time,  attention and skill
      for  (______days)  per  month  and  during  this  time use his  reasonable
      endeavours  to develop the business and interests of the Group and perform
      his duties to the best of his ability.

12.2  The  Company  recognises  and  acknowledges  the  Director's  rights to be
      employed by other  companies or to be the  director of another  company of
      which  he is a major  shareholder,  but  the  Director  undertakes  to the
      Company that during his  employment  with the Company or any subsidiary of
      the  Company he shall not,  whether as  principal,  partner,  shareholder,
      director, manager, employee,  contractor,  consultant, agent either on his
      own account or for any other person or otherwise howsoever:

      12.2.1 directly or indirectly  engage or be concerned or interested in any
             business in competition with any business carried on by the Company
             or any of its subsidiaries from time to time, solicit the custom of
             any  person  who  is a  supplier  to  the  Company or  any  of  its
             subsidiaries or to whom the Company or any of its subsidiaries  has
             made a quotation  with a view to such person becoming a customer of
             any such  businesses or has a continuing course of dealing with the
             Company or any of its subsidiaries,  or

      12.2.2 endeavour  to  entice   away  from  the   Company  or  any  of  its
             subsidiaries any person who is an employee of the Company or any of
             its subsidiaries.

12.3  The  Director  undertake  to the  Company  that he shall have no  material
      interest  in any  contract  (other than his own  contract  of  employment)
      entered into by the Company or any of its  subsidiaries  without the prior
      consent of the Board.

12.4  The Director  undertakes  to the Company that he shall not,  either during
      the   continuance  of  his  employment  by  the  Company  or  any  of  its
      subsidiaries  thereafter  or for so  1ong  as he is a  shareholder  of the
      Company  or  any  of its  subsidiaries  or  thereafter  (except  with  the
      authority  of the Board or if  required  by law) use to the  detriment  or
      prejudice  of the  Company or any of its  subsidiaries  or,  except in the
      proper  course of his duties,  divulge to any person,  any trade secret or
      confidential information concerning the business or affairs of the Company
      or any of its subsidiaries


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Agreement between Company and Director
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PROVIDED THAT the  restriction  shall cease to apply to information or knowledge
which comes into the public  domain  otherwise  than by reason of default of the
Director concerned.

12.5  The Director  undertakes to the Company that if his position (if any) as a
      director of the Company or any of its  subsidiaries is terminated he shall
      not for a period of six months  from the date of such  termination  (which
      shall be taken  to mean  the  expiry  of his  notice  period)  whether  as
      principal, partner, shareholder,  director, manager, employee, contractor,
      consultant,  agent  either on his own  account or for any other  person or
      otherwise howsoever:

      12.5.1  within  the  United  Kingdom  and in  competition  with any of the
              businesses carried on by the Company or any of its subsidiaries at
              the date of termination,  solicit the custom of any person who (as
              at the date of such  termination)  is a supplier to the Company or
              any of its subsidiaries or to whom (as at the date of termination)
              the Company or any of its subsidiaries has made a quotation with a
              view to such person  becoming a customer of any such businesses or
              whom at the date of such  termination  either is a customer of any
              such  businesses or has a  continuing  course  of dealing with the
              Company or any of its subsidiaries, or

      12.5.2  endeavour   to  entice  away  from  the  Company  or  any  of  its
              subsidiaries any person who at the date of such termination was an
              employee of the Company or any of its subsidiaries.

PROVIDED THAT sub-clauses 12.5.1 and 12.5.2 of the Clause shall not apply if the
Director has been  wrongfully  or unfairly  dismissed or  wrongfully or unfairly
constructively  dismissed  within  the  meaning  of  the  Employment  Protection
(Consolidation) Act 1978.

      12.5.3  The Director agrees that if such  restrictions as are contained in
              this Clause as a whole shall be judged by a competent  court to go
              beyond what is reasonable  for the  protection of the interests of
              the Company,  but would be reasonable  and  enforceable if certain
              words were deleted or if the area or time  covered  were  reduced,
              the same restrictions  shall apply with such words deleted and the
              said area or time  shall be reduced by  whatever  extent  shall be
              necessary to make such  restrictions  valid and effective and such
              restrictions shall apply as so modified.

      13    INVENTIONS

      13.1  The parties  foresee that the Director may make,  discover or create
            Intellectual  Property  in the  course  of  his  duties  under  this
            Agreement  and agree that in this respect the Director has a special
            obligation  to  further  the  interests  of  the  Company.

      13.2  In  accordance  with the  provisions  of the  Patent  Act 1977,  the
            Registered  Designs Act 1949 and the Copyright,  Designs and Patents
            Act 1988, if at any time in the course of his employment  under this
            Agreement  the Director  makes or discovers or  participates  in the
            making or discovery of any


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Agreement between Company and Director
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      Intellectual Property relating to or capable of being used in the business
      for the time being  carried on by the Company or any of its  subsidiaries,
      full  details  of  the   Intellectual   Property   shall   immediately  be
      communicated  by him to the Company and shall be the absolute  property of
      the Company.  At the request and expense of the Company the Director shall
      give and supply all such information, data, drawings and assistance as may
      be required to enable the Company to exploit the Intellectual  Property to
      the best advantage and shall execute all documents and do all things which
      may be necessary or desirable for obtaining patents or other protection of
      the  Intellectual  Property in such parts of the world as may be specified
      by the  Company  and for  vesting  the  same in the  Company  or as it may
      direct.

13.3  If the  Director  makes or  discovers  or  participates  in the  making or
      discovery of any  Intellectual  Property  during his employment  under the
      Agreement  but which is not the property of the Company under Clause 13.2,
      the Company shall,  subject only to the provisions of the Patent Act 1977,
      have the right to acquire for itself or its nominee the Director's  rights
      in the Intellectual  Property within 3 months after disclosure pursuant to
      Clause  13.2 on fair and  reasonable  terms to be agreed or  settled  by a
      single arbitrator.

13.4  The  Director  waives all his Moral  Rights as  defined in the  Copyright,
      Designs and Patents Act 1988 in respect of any acts of third  parties done
      with the Company's authority in relation to the Intellectual Property (the
      property of the Company by virtue of Clause 13.2 hereof).

13.5  Rights and  obligations  under this Section shall  continue in force after
      termination of this Agreement in respect of Intellectual  Property made or
      discovered during the Director's employment under this Agreement and shall
      be binding upon his representatives, heirs and assigns.

14    CONFIDENTIALITY

14.1  The  Director  is aware  that in the course of his  employment  under this
      Agreement  he will have access to and be  entrusted  with  information  in
      respect of the  business  and  financing  of the Company and its  dealings
      transactions and affairs and likewise in relation to its subsidiaries, all
      of which information is or may be confidential.

14.2  The Director  shall not (except in the proper course of his duties) during
      or after the  period of  employment  under this  Agreement  divulge to any
      person  whomsoever  or  otherwise  make  use of (and  shall  use his  best
      endeavours to prevent the  publication  or disclosure of) any trade secret
      or any confidential  information concerning the business of the Company or
      any of its  subsidiaries  or any of its/their  dealings,  transactions  or
      affairs.

14.3  All notes and memoranda of any trade secrets or  confidential  information
      concerning the business of the Company or any of its  subsidiaries  or any
      of its/their suppliers, agents, distributors or customers which shall have
      been acquired,  received or made by the Director  during the course of his
      employment  shall be the property of the Company and shall be  surrendered
      by  the  Director  to  someone  duly  authorised  in  that  behalf  at the
      termination of his


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Agreement between Company and Director
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      employment or at the request of the Board at any time during the course of
      his employment.

15    TERMINATION OF DIRECTORSHIP

      The  employment  of the  Director  under this  Agreement  shall  terminate
      automatically  in the event of him ceasing to be a Director of the Company
      and in that event the Director shall have no claim for damages against the
      Company  unless he shall so cease by virtue of a resolution  passed by the
      members of the Company in general meeting to remove him as director and at
      the same time of such  removal  the Company is not  otherwise  entitled to
      terminate his employment under this Agreement.

16    SUMMARY TERMINATION OF EMPLOYMENT

The  employment of the Director may be terminated by the Company  without notice
or payment in lieu of notice:

16.1  in the event of any serious  (the  Director  having been warned in respect
      thereof) persistent breach or non-observance by the Director of any of the
      stipulations contained in the Agreement, or

16.2  if the Director has an interim  receiving order made against him,  becomes
      bankrupt or makes any  composition  or enters into any deed of arrangement
      with his creditors, or

16.3  if the Director is convicted of any  arrestable  criminal  offence  (other
      than an offence under  road-traffic  legislation  in the United Kingdom or
      elsewhere for which a fine or non-custodial penalty is imposed), or

16.4  if the Director is disqualified  from holding office in another company in
      which he is concerned or interested  because of wrongful trading under the
      Insolvency Act 1983, or

16.5  if the Director shall become of unsound mind or become a patient under the
      Mental Health Act 1983, or

16.6  if the Director is convicted of an offence under the Companies  Securities
      (Insider  Dealing) Act 1985 or under any other present or future statutory
      enactment or regulations relating to insider dealing, or

16.7  if the Director resigns as a director of the Company otherwise than at the
      request of the Company

17    RESIGNATION FROM DIRECTORSHIPS UPON TERMINATION

Upon the termination by whatever means of this Agreement:

17.117.1    the Director shall at the request of the Company  immediately resign
      from office as a director of the Company and from such offices held by him
      in subsidiaries as may be so requested  without claim for compensation and
      in the event of his  failure so to do the  Company  is hereby  irrevocably
      authorised to


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Agreement between Company and Director
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      appoint some person in his name and on his behalf to sign and deliver such
      resignation or resignations to the Company or any of its subsidiaries, and

17.2  the  Director  shall not  without  the  consent of the Company at any time
      thereafter represent himself still to be connected with the Company or any
      of its subsidiaries.

18    RECONSTRUCTION OR AMALGAMATION

      If the  employment of the Director  under this  Agreement is terminated by
      reason of the liquidation of the Company for the purpose of reconstruction
      or amalgamation and the Director is offered employment with any concern or
      undertaking resulting from the reconstruction or amalgamation on terms and
      conditions not less  favourable  than the terms of this Agreement then the
      Director  shall  have no claim  against  the  Company  in  respect  of the
      termination of his employment under this Agreement.

19    NOTICES

19.1  Any  notice  or other  communication  under  or in  connection  with  this
      Agreement shall be in writing and shall be delivered personally or sent by
      first class post pre-paid  recorded delivery (and air-mail if overseas) or
      by  telex  or by  telefax  to the  party  due to  receive  the  notice  or
      communication  at its  address  set out in this  Agreement  or such  other
      address as either party may specify by notice in writing to the other.

19.2  In the  absence  of  evidence  of  earlier  receipt  any  notice  or other
      communication shall be deemed to have been duly given:

      19.2.1 if delivered  personally,  when left at the address  referred to in
      Clause  19.1;

      19.2.2 if sent by mail other than air-mail, two days after posting it;

      19.2.3 if sent by air-mail, six days after posting it;

      19.2.4 if sent by telex, when the proper answer back is received, and;

      19.2.5 if sent by telefax, on completion of its transmission.

20    STATUTORY INFORMATION

The schedule to this Agreement set out  information  required to be given to the
Director by the Employment Protection (Consolidation) Act 1978 as amended.

21    GOVERNING LAW AND JURISDICTION

This Agreement is governed by and shall be construed in accordance with the laws
of England,  and the parties hereto submit to the non-exclusive  jurisdiction of
the English courts.


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Agreement between Company and Director
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22    ENTIRE AGREEMENT

This  Agreement  contains  the entire  understanding  between  the  parties  and
supersedes  all previous  agreements and  arrangements  (if any) relating to the
employment  of the  Director by the Company  (which shall be deemed to have been
terminated by mutual consent).

23    COUNTERPARTS

This   Agreement  may  be  executed  by  the   different   parties  in  separate
counterparts,  each of which when  executed and  delivered  shall  constitute an
original  but  both  of  which  shall  together  constitute  one  and  the  same
instrument.

IN WITNESS of which the parties have executed this Agreement as follows:


---------------------------------
DIRECTOR                                        ---------------------
                                                Date:


---------------------------------
For COMPANY
                                                ---------------------
                                                Date: