<PAGE>
 
                                                                   Exhibit 10.45


                           Dated 1st September 1995



                               SERVICE AGREEMENT

                                    Between

                               INDEX FX LIMITED

                                      And

                               MR SIMON DRABBLE



                               M.W. Cornish & Co
                                  Solicitors
                                 11 Old Jewry
                                London EC2R 8DU

                                     -116-
<PAGE>
 
                               SERVICE AGREEMENT

                        Dated                     1995

PARTIES

(1) INDEX FX LIMITED whose registered office is at 37 Lombard Street, London
    EC3V 9BQ (the "Company"); and

(2) MR SIMON DRABBLE of Dublin Farmhouse, Wherwell, Nr. Andover, Hampshire SP11
    7JP (the "Executive").

1.  INTERPRETATION

In this Agreement:--

(a) the "Board" means the board of directors of the Company;

(b) the "Commencement Date" means the 1st day of September 1995;

(c) the "Group" means:

    (i)   the Company;

    (ii)  the Company's holding company (if any);

    (iii) any other subsidiary of the Company or the Company's holding company;
          and

    (iv)  any other company in which the Company is interested and whose name
          is notified to the Executive by the Company as being a member of the
          Group

    and (where the context so admits) includes any member of the Group. For this
    purpose "holding company" and "subsidiary" have the meanings given to them
    by sections 736, 736A and 736B of the Companies Act 1985;

                                     -117-
<PAGE>
 
(d) "Net Income of the Company" means 50% (fifty per cent.) of the gross income
    of the Company resulting from business undertaken by the Team (including
    introductory commissions from Index Futures Group Inc.) less 50% (fifty
    percent) of the costs incurred by the Company in supporting the Team
    including, for the avoidance of doubt, the items and the indicative costs
    set out at Appendix 1 and trading errors and unpaid debts of the Team's
    clients.

(e) the "Team" means Simon Drabble, Graham Wellesley and Lorenzo Naldini and
    such other persons as may be agreed from time to time by the parties.

(f) the "Termination Date" means the date on which the Executive's employment
    under this Agreement ceases;

(g) reference to any statutory provision includes a reference to that provision
    as amended, extended or re-enacted and to any statutory replacement thereof
    (either before or after the date of this Agreement).

2.  APPOINTMENT, TERM AND CONTINUITY

(a) Subject to the provisions of this Agreement, the Executive is appointed and
    shall serve the Company as a Director from the Commencement Date until his
    employment is terminated by either party giving to the other not less than
    [three months'] notice expiring at any time.

(b) The Executive's period of continuous employment with the Company for the
    purposes of the Employment Protection (Consolidation) Act 1978 commenced on
    1st day of September 1995.

3.  REMUNERATION

(a) The Executive shall be entitled to a commission share of the Net Income of
    the Company, his proportion of such commission to be determined by agreement
    with the other members of the Team and notified to the Company in writing.

(b) The Company shall pay the Executive a draw against commissions to be earned
    under sub-clause (a) above at the rate of US$8,565 per month or at such
    other rate as the Board may from time to time decide. Such draw shall be
    paid monthly in arrears on the last working day in every month and shall be

                                     -118-
<PAGE>
 
    repayable by deduction from the commission share due in future quarters to
    the Executive pursuant to (c) below if the commissions earned by the Team
    under (a) above are less than US$25,695 in aggregate in any month or on
    average over any quarterly period Provided That the draw against commissions
    paid to the Executive in the first three months of his employment shall not
    be repayable if the commissions earned by the Team under (a) above are less
    than US$25,695 in aggregate in any of those three months or on average over
    such period.

(c) 50% (fifty per cent.) of the commission share of the Executive under (a)
    above shall be payable quarterly in arrears after deduction of any draw
    against commission under (b) above with the balance of such commission share
    being payable at the Company's financial year end.

4.  EXPENSES

    The Company shall reimburse the Executive all reasonable out of pocket
    expenses properly incurred by him on the Company's business and evidenced to
    the Company's reasonable satisfaction provided that such expenses shall not
    exceed such amounts as may be agreed from time to time unless approved in
    advance.

5.  DUTIES

(a) The Executive shall act as a broker in spot and forward foreign exchange in
    the inter-bank market and as an introducer of clients to other Group
    companies in relation to on-exchange futures and options broking and
    clearing business. The Executive shall also perform such other duties and
    exercise such powers as are consistent with his appointment and as are from
    time to time given to him by the Board and shall use his best endeavours to
    futher the interests of the Group. The Executive shall comply with all
    policies and directives of the Board and the rules of the Securities and
    Futures Authority Limited ("SFA") and in particular personal account dealing
    and other regulatory notices and requirements in compliance with the SFA
    rules.

                                     -119-
<PAGE>
 
(b) Without prejudice to sub-clause (a) the Executive shall at all times keep
    the Board fully informed of his conduct of his duties on behalf of the
    Company and, as the case may be, of any other member of the Group when
    appropriate and shall promptly provide such information and explanations as
    may be requested from time to time by the Board.

(c) The Executive's normal working hours shall be [7.30 a.m. to 5.30 p.m.] on
    Mondays to Fridays inclusive with one hour for lunch and he shall devote
    such further time as may be necessary for the proper performance of his
    duties. Pressure of work may well necessitate that longer hours are worked.

(d) The Company may require the Executive to perform his duties anywhere within
    or outside the United Kingdom in the ordinary course of his duties.

(e) During his employment the Executive shall not, except with the prior written
    consent of the Board, be directly or indirectly engaged, concerned or
    interested in any other business or occupation provided that he may hold
    and/or be interested in (for the purpose of investment only and not
    exceeding one per cent. of the issued share capital of any company) any
    securities listed on a recognised stock exchange or dealt in on any other
    public securities market.

(f) There shall be no obligation on the Company to vest in or assign to the
    Executive any powers or duties or to provide any work for him, and the
    Company may at any time or from time to time during any period of notice as
    specified in clause 2(a) (or in circumstances in which it reasonably
    believes that the Executive is guilty of misconduct or in breach of this
    Agreement, in order that the circumstances giving rise to that belief may be
    investigated) suspend the Executive from the performance of his duties or
    exclude him from any premises of the Company and need not give any reason
    for so doing. During such suspension or exclusion the Company may require
    the Executive to be available by telephone during normal working hours.
    Salary and other benefits will not cease to be payable by reason only of
    such suspension or exclusion.

                                     -120-
<PAGE>
 
6.  HOLIDAYS

(a) In addition to public holidays the Executive shall be entitled to [25]
    working days' paid holiday in each calendar year which shall be taken at
    such time or times as may be agreed between the Executive and the Board.
    Holiday entitlement during each of the first and last calendar years of
    employment shall be in direct proportion (to the nearest day) to the length
    of the Executive's service during such year. The Executive shall have no
    claim against the Company if he does not take his full holiday entitlement
    and holiday not taken in one calendar year may not be carried forward in
    whole or in part to a subsequent calendar year.

(b) Reasonable notice of proposed holiday dates must be given by the Executive
    and the dates agreed with the Board. No holiday may be taken by the
    Executive after notice to terminate the Executive's employment has been
    given. On termination of his employment the Executive shall be entitled to
    remuneration in lieu of any outstanding holiday entitlement and the Company
    shall have the right to make an appropriate deduction from his final
    remuneration in respect of any excess holiday taken by the Executive.

(c) The retirement age for the Executive shall be 65.

7.  SECRECY

(a) The Executive shall not (except in the proper course of his duties
    hereunder), either before or after the Termination Date, make use of or
    divulge to any person, and shall use his best endeavours to prevent the
    publication or disclosure of, any trade secret or any other private,
    confidential or secret information concerning the business or finances of
    the Group or any of its dealings, transactions or affairs or concerning any
    third party with which the Group has dealt and all notes, memoranda and
    other records of such trade secrets or information made or received by the
    Executive during the course of his employment hereunder shall be the
    property of the Company and shall be surrendered by him to someone duly
    authorised on their behalf at the termination of his employment with the
    Company or at the request of the Board at any time during the course of his
    employment. In this Agreement confidential information includes, but is not
    limited to, the following:--

                                     -121-
<PAGE>
 
    (i)   information relating to the Group's clients, prospective clients,
          persons to whom the Group has made presentations and for whom
          quotations have been prepared, and the requirements of such persons in
          terms of the Group's business or services;

    (ii)  information relating to the Group's suppliers, agents and
          distributors;

    (iii) information relating to intellectual property in which the Group has
          an interest, the marketing of the Group's products and services and
          the fee arrangements in force between the Group and its clients.

(b) Whenever requested to do so by the Company, and in any event upon
    termination of his employment with the Company, the Executive shall hand
    over to the Company all models, equipment, documents and records (including
    all computer software and programs), and other things in his possession or
    control which relate to the business or affairs of the Group or of any third
    party with which the Group has had dealings and no copies shall be retained
    by him. As between the Company and the Executive all such documents and
    records are deemed to be the property of the Company.

(c) The restrictions in sub-clause (a) shall cease to apply to information or
    knowledge which may (otherwise than through the Executive's fault) become
    available to the public generally.

(d) These obligations are in addition to and not in substitution for any
    obligations imposed upon the Executive by law or otherwise.

8.  RESTRICTIONS

(a) The Executive shall not at any time during a period of six months after the
    Termination Date and in material competition with any business carried on by
    the Company or any other member of the Group at the Termination Date solicit
    the custom of or deal with any person, firm or company which was a client of
    or a prospective client of material importance to the Company or any other
    member of the Group and with whom the Executive had communicated or
    associated to any material extent in the course of his employment during the
    twelve months preceding the Termination Date unless the Company ceases to
    carry on inter-bank foreign business.

                                     -122-
<PAGE>
 
(b) The Executive shall not at any time after the Termination Date represent
    himself or cause or permit himself to be represented as being in any way
    connected with the Group.

(c) The Executive shall be bound by the following restrictions in respect of any
    employee of the Group who is an employee of the Company or any other member
    of the Group at the Termination Date or at any time during the preceding
    twelve months in an executive, managerial, technical or sales capacity:--

    (i)  the Executive shall not at any time during a period of six months from
         the Termination Date employ or offer to any such employee any
         alternative employment or attempt in any way to persuade any such
         employee to enter any alternative employment or to leave the employment
         of the Group.

    (ii) the Executive shall during a period of six months from the Termination
         Date use his best endeavours to prevent any person, firm or company
         with whom he may be engaged or connected from employing or offering to
         any such employee any alternative employment or from attempting in any
         way to persuade any such employee to enter into any alternative
         employment or to leave the employment of the Group.

(d) The Executive acknowledges that in all the circumstances of this Agreement
    (including, but not limited to, the remuneration payable to the Executive
    hereunder) the restrictions and provisions herein contained are reasonable
    and necessary for the protection of the Group's legitimate business
    interests and he further acknowledges that, having regard to those
    circumstances, such restrictions and provisions do not work harshly on him.

(e) Notwithstanding sub-clause (d), the parties agree that the covenants set out
    in this clause shall be separate and severable and enforceable accordingly
    and, if any of the above periods of six months following the Termination
    Date referred to in sub-clauses (a), (b) and (c) shall be adjudged to go
    beyond what is reasonable in all the circumstances for the protection of the
    Group, a period or periods of three months following the Termination Date
    shall be substituted therefor.

                                     -123-
<PAGE>
 
(f) The undertakings in this clause shall cover all actions by the Executive in
    whatever capacity and whether directly or indirectly through or with any
    third party, agent, company, partnership, employee, employer, associate
    (within the meaning of section 435 of the Insolvency Act 1985) or trust
    which if done by him personally would breach the provisions of this clause.

(g) These obligations are in addition to and not in substitution for any
    obligations imposed upon the Executive by law or otherwise.

9.  INJUNCTIVE RELIEF FOR SECRECY AND RESTRICTIONS

    The Executive acknowledges that the Company will have no adequate remedy at
    law if the Executive violates the terms of the provisions of either of
    clauses 7 ("Secrecy") or 8 ("Restrictions") above. In the event of any such
    violation, the Company shall have the right, in addition to and without
    prejudice to any other rights it may have, to obtain in any court of
    competent jurisdiction injunctive relief or specific performance to restrain
    any breach or threatened breach of this Agreement.

10. DISCIPLINARY AND GRIEVANCE PROCEDURE

    In the execution of his duties the Executive shall conduct himself in a
    manner befitting his appointment hereunder. If the Executive is dissatisfied
    with any disciplinary decision or wishes to seek redress for any grievance
    relating to his employment he shall refer it to Charles Romilly whose
    decision shall be final.

11. TERMINATION

(a) The Executive's employment may be terminated by the Company forthwith by
    notice if:--

    (i)    he makes any arrangement or composition with his creditors generally
           or there are grounds under section 267 of the Insolvency Act 1986 for
           the presentation of a creditor's petition for a bankruptcy order to
           be made against him or an interim receiver of his property is
           appointed under section 286 of that Act;

                                     -124-
<PAGE>
 
    (ii)   he is convicted of a criminal offence as a result of which he is
           sentenced to a term of imprisonment;

    (iii)  he commits any serious breach of his obligations to the Company;

    (iv)   having committed any breach of his obligations to the Company he
           fails to rectify such breach (if reasonably capable of rectification)
           or commits a further or continuing breach after warning by the
           Company;

    (v)    his conduct is in the opinion of the Board prejudicial to the
           interests of the Group. The Board may take into account a conviction
           for any criminal offence not covered by sub-clause (ii);

    (vi)   being a director of any company in the Group he resigns his
           directorship or becomes prohibited by law from being a director;

    (vii)  he becomes of unsound mind or becomes a patient under the Mental
           Health Act 1983;

    (viii) by reason of ill health or incapacity he is prevented from performing
           his duties for periods which have exceeded (or in the reasonable
           estimation of the Board are likely to exceed) in aggregate twenty-six
           weeks in any twelve month period.

    (ix)   he ceases to be authorised to conduct investment business in the
           United Kingdom.

(b) Upon termination of his employment howsoever arising the Executive shall
    resign without claim for compensation from all directorships and other
    offices within the Group and should he fail to do so the Company is hereby
    irrevocably authorised by the Executive to appoint some person in his name
    and on his behalf as his attorney to sign any documents and do all things
    necessary or requisite to give effect thereto.

                                     -125-
<PAGE>
 
(c) Upon the termination of the Executive's employment for whatever reason the
    Company will be entitled to deduct from any payments then due or becoming
    due to the Executive (whether in respect of any period before such
    termination or not) any moneys which may then be or become due or may become
    due thereafter from the Executive to the Company or any other member of the
    Group.

(d) If the Executive's employment shall be terminated by reason only of the
    liquidation of the Company for the purpose of amalgamation or reconstruction
    and the Executive shall be offered employment with any concern or
    undertaking resulting from such amalgamation or reconstruction on terms no
    less favourable than the terms of this Agreement the Executive shall have no
    claim against the Company in respect of the termination of his employment
    hereunder.

12. NOTICES

    All notices under this Agreement shall be in writing. Notices to the Company
    may be given by the Executive either personally to Charles Romilly or by
    prepaid first class letter, facsimile or telex addressed to the Company at
    its registered office for the time being. Notices to the Executive may be
    given by the Company either personally or by prepaid first class letter,
    facsimile or telex addressed to the Executive at his last known address or
    his place of work. Any such notice unless given personally shall be deemed,
    if given by letter, to have been served 48 hours from the time of posting
    and in proving service by post it shall be sufficient to show that the
    letter was properly addressed and posted in accordance with the provisions
    of this clause and, if given by facsimile or telex, to have been served at
    the time it is transmitted if transmitted between 9.00 am and 5.30 pm London
    time on a business day or, if not so transmitted, at 9.00 am London time on
    the first business day thereafter. In proving service by facsimile or telex
    it shall be sufficient to show that the transmission was properly made and
    that the transmitting device was connected to a device with a facsimile or
    telex telephone number reasonably believed to be that of the party to be
    served.

                                     -126-
<PAGE>
 
13. PREVIOUS AGREEMENTS

(a) This Agreement supersedes any previous agreement (whether written, oral or
    implied) between any member of the Group and the Executive relating to his
    employment which, without prejudice to his right to receive sums accrued due
    thereunder, shall be void from the Commencement Date.

(b) The Executive acknowledges and warrants that there are no agreements or
    arrangements, whether oral, written or implied, between any member of the
    Group and the Executive other than those expressly set out in this Agreement
    and that he is not entering into this Agreement in reliance on any
    representation not expressly set out herein.

14. GOVERNING LAW

    This Agreement shall be governed by and construed in accordance with English
    law and the Executive hereby irrevocably agrees for the exclusive benefit of
    the Company that the English Courts are to have jurisdiction to settle any
    disputes which may arise out of or in connection with this Agreement.

EXECUTED (in the case of the Executive as a deed) on the date appearing at the
beginning of this document.

SIGNED by  /s/ SIMON DRABBLE
the duly authorised representative of
THE COMPANY in the presence of:--

Witness: /s/ CHARLES ROMILLY

SIGNED AND DELIVERED as a deed 
by THE EXECUTIVE in the presence of:--

Witness: /s/ CHARLES ROMILLY

0523/MWC
        
                                     -127-