<PAGE>

                                                                     Exhibit 4.4



            ----------------------------------------------------
              THE WILLIS GROUP HOLDINGS LIMITED NON-EMPLOYEE
                       DIRECTORS SHARE OPTION SCHEME
            ----------------------------------------------------


<PAGE>

                                    CONTENTS

CLAUSE                                                               PAGE

1.   Definitions And Interpretation...................................1
2.   Grant Of Options.................................................1
3.   Limits...........................................................2
4.   Exercise Of Options..............................................2
5.   Cash Equivalent..................................................3
6.   Merger, Consolidation, Exchange, Acquisition, Liquidation or
     Dissolution......................................................4
7.   Adjustment Of Options............................................5
8.   Alterations......................................................5
9.   Miscellaneous....................................................5








<PAGE>



1.    DEFINITIONS AND INTERPRETATION

1.1   In this Scheme, unless the context otherwise requires:-

      "THE BOARD" means the board of directors of the Company or a committee
      appointed by them;

      "THE COMPANY" means Willis Group Holdings Limited (registered in Bermuda);

      "THE GRANT DATE" in relation to an option  means the date on which the
      option was granted;

      "GROUP MEMBER" means:

      1.1.1 a Participating Company or a body corporate which is the Company's
            holding company or a subsidiary of the Company's holding company; or

      1.1.2 a body corporate which is a subsidiary undertaking of a body
            corporate within paragraph 1.1.1 above and has been designated by
            the Board for this purpose;

      "NON-EMPLOYEE DIRECTOR" means a member of the Board who is not an employee
      of the Company or any of its Subsidiaries;

      "PARTICIPANT" means a person who holds an option granted under this
      Scheme;

      "PARTICIPATING COMPANY" means the Company or any Subsidiary or any company
      which is not under the control of any single person, but is under the
      control of two persons, one of them being the Company;

      "SUBSIDIARY" means a body corporate which is a subsidiary of the Company.

2.    GRANT OF OPTIONS

2.1   Subject to Rule 3, the Board may by deed grant to any Non-Employee
      Director in any calendar year an option to subscribe for shares in the
      Company with a market value of $40,000 or such other amount as the Board
      shall determine from time to time , upon the terms set out in this Scheme
      and upon such other objective terms as the Board may specify. The terms of
      grant may include a term that the Participant enter into an agreement or
      election under which the Participant agrees to pay his employer's social
      security or National Insurance liability (or reimburse the employer for
      such liability) in any jurisdiction arising on exercise of the option. A
      Non-Employee Director may only be granted one option under this Scheme in
      each calendar year.

2.2   For the purposes of Rule 2.1, the market value of shares shall be on a per
      share basis for any given day, (i) if the Shares are not listed on any
      stock exchange, the fair market value per share, as determined by the
      Board on the relevant calculation date, and (ii) if the shares are listed
      on a stock exchange, the price per share equal to the average of the last
      sale price of the shares on each of the ten trading days prior to the
      relevant calculation date on the New York Stock Exchange or, if there
      shall have been no sales on such exchange on any such trading day, the
      average of the closing bid and asked prices on such exchange at the end of
      such trading day or if there is no such bid and asked price on the next
      preceding date when such bid and asked price occurred or, if the shares
      shall


<PAGE>

      not be so listed, the average of the closing sales prices as reported by
      NASDAQ at the end of the relevant calculation date in the over-the-counter
      market.

2.3   The price at which shares may be acquired by the exercise of an option
      granted under this Scheme shall be the nominal value of those shares.

2.4   An option may only be granted:

      2.4.1 within the period of 6 weeks beginning with:

            (a)   the date on which this Scheme is approved and adopted by the
                  Company; or

            (b)   the tenth day after the Company announces its results for any
                  period; or

      2.4.2 at any other time when the circumstances are considered by the Board
            to be sufficiently exceptional to justify its grant; and

      2.4.3 within the period of 10 years beginning with the date on which this
            Scheme is adopted by the Company.

2.5   An option granted to any person:

      2.5.1 shall not, except as provided in Rule 4.4, be capable of being
            transferred by him; and

      2.5.2 shall lapse forthwith if he is adjudged bankrupt.

3.    LIMITS

3.1   No options shall be granted in any year which would, at the time they are
      granted, cause the number of shares in the Company allocated under this
      Scheme to exceed 100,000 shares.

3.2   Any option granted under this Scheme shall be limited and take effect so
      that the above limits are complied with.

4.    EXERCISE OF OPTIONS

4.1   The exercise of any option shall be effected in the form and manner
      prescribed by the Board and, unless the Board determines otherwise, any
      notice of exercise shall take effect only when received by the Company
      together with the relevant exercise monies or an agreement to provide such
      monies pursuant to arrangements acceptable to the Company.

4.2   An option granted under this Scheme may be exercised at any time after the
      Grant Date.

4.3   If any Participant dies at a time when he is a Non-Employee Director, any
      option may (and must, if at all) be exercised by his personal
      representatives within 12 months after the date of his death.

4.4   If any Participant ceases to be a Non-Employee Director (otherwise than by
      reason of his death), he may exercise any option within 12 months after
      the date he so ceased.


<PAGE>

4.5   A Participant shall not be treated for the purposes of Rule 4.4 as ceasing
      to be a Non-Employee Director until such time as he is no longer a
      Non-Employee Director of any Group Member.

4.6   Notwithstanding any other provision of this Scheme, an option may not be
      exercised after the expiration of the period of 10 years (or such shorter
      period as the Board may have determined before its grant) beginning with
      the Grant Date.

4.7   An option may not be exercised unless:

      4.7.1 the Board considers that the issue or transfer of shares pursuant to
            such exercise would be lawful in all relevant jurisdictions; and

      4.7.2 in a case where, if the option were exercised, a Group Member would
            be obliged to (or would suffer a disadvantage if it were not to)
            account for any tax (in any jurisdiction) for which the person in
            question would be liable by virtue of the exercise of the option
            and/or for any social security contributions that would be
            recoverable from the person in question (together, the "Tax
            Liability"), that person has either:

            (a)   made a payment to the Group Member of an amount at least equal
                  to the Company's estimate of the Tax Liability; or

            (b)   entered into arrangements acceptable to that or another Group
                  Member to secure that such a payment is made (whether by
                  authorising the sale of some or all of the shares on his
                  behalf and the payment to the Group Member of the relevant
                  amount out of the proceeds of sale or otherwise)

4.8   Within 30 days after an option has been exercised by any person, the Board
      shall allot to him (or a nominee for him) the number of shares in respect
      of which the option has been exercised.

4.9   All shares allotted under this Scheme shall rank equally in all respects
      with the shares of the same class then in issue except for any rights
      attaching to such shares by reference to a record date prior to the date
      of the allotment.

5.    CASH EQUIVALENT

5.1   Where an option has been exercised by any person in respect of any number
      of shares, and those shares have not yet been allotted to him in
      accordance with Rule 4.8, the Board may determine that, in substitution
      for his right to acquire such number of those shares as the Board may
      decide (but in full and final satisfaction of his said right), he shall be
      paid by way of additional emoluments a sum equal to the cash equivalent of
      that number of shares.

5.2   The CASH EQUIVALENT of any shares is the amount by which the Board's
      opinion of the market value of those shares on the day immediately
      preceding the date on which the option was exercised (or, if at the
      relevant time shares of the same class as those shares were listed on the
      New York Stock Exchange, the closing price per share on the dealing

<PAGE>

      day immediately preceding that date) exceeds the price at which those
      shares may be acquired by the exercise of the option.

5.3   Subject to Rule 5.4, as soon as reasonably practicable after a
      determination has been made under Rule 5.1 that a person shall be paid a
      sum in substitution for his right to acquire any number of shares:

      5.3.1 the Company shall pay to him or procure the payment to him of that
            sum in cash; and

      5.3.2 if he has already paid the Company for those shares, the Company
            shall return to him the amount so paid by him.

5.4   If the Board in its discretion so decides:

      5.4.1 the whole or part of the sum payable under Rule 5.3.1 shall, instead
            of being paid to the person in question in cash, be applied on his
            behalf in subscribing for shares in the Company at a price equal to
            the market value (or, as the case may be, the closing price) by
            reference to which the cash equivalent is calculated, or in
            purchasing such shares, or partly in one way and partly in the
            other, and

      5.4.2 the Company shall allot to him (or his nominee) or procure the
            transfer to him (or his nominee) of the shares so subscribed for or
            purchased.

5.5   There shall be made from any payment under this Rule 5 such deductions (on
      account of tax or similar liabilities) as may be required by law or as the
      Board may reasonably consider to be necessary or desirable.

6.    MERGER, CONSOLIDATION, EXCHANGE, ACQUISITION, LIQUIDATION OR DISSOLUTION

6.1   In its absolute discretion, and on such terms and conditions as it deems
      appropriate, coincident with or after the grant of any option, the Board
      may provide that such option cannot be exercised after the merger,
      amalgamation pursuant to Bermuda law, or other consolidation of the
      Company into another company, the exchange of all or substantially all of
      the assets of the Company for the securities of another company, the
      acquisition by another company of 80% or more of the Company's then
      outstanding shares of voting stock or the recapitalization,
      reclassification, liquidation or dissolution of the Company, and if the
      Board so provides, it shall, on such terms and conditions as it deems
      appropriate in its absolute discretion, also provide, either by the terms
      of such option or by a resolution adopted prior to the occurrence of such
      merger, consolidation, exchange, acquisition, recapitalization,
      reclassification, liquidation or dissolution, that, for some period of
      time prior to such event, such option shall be exercisable as to all
      shares subject thereto, notwithstanding anything to the contrary herein
      and that, upon the occurrence of such event, such option shall terminate
      and be of no further force or effect; provided, however, that the Board
      may also provide, in its absolute discretion, that even if the option
      shall remain exercisable after any such event, from and after such event,
      any option shall be exercisable only for the kind and amount of securities
      and/or other property, or the cash equivalent thereof, receivable as a
      result of such event by the holder

<PAGE>

      of a number of shares for which such option could have been exercised
      immediately prior to such event.

7.    ADJUSTMENT OF OPTIONS

7.1   In the event of any variation of the share capital of the Company
      including a demerger, special dividend or other event which, in the
      opinion of the Board would affect the share price to a material extent,
      then the Board may make such adjustments as it considers appropriate under
      Rule 7.2.

7.2   An adjustment made under this Rule shall be to one or more of the
      following:

      7.2.1 the number of shares in respect of which any option may be
            exercised;

      7.2.2 where any such option has been exercised but no shares have been
            allotted pursuant to such exercise, the number of shares which may
            be so allotted.

8.    ALTERATIONS

8.1   Subject to Rules 8.2, the Board may at any time alter this Scheme, or the
      terms of any option granted under it.

8.2   No alteration to the disadvantage of any Participant shall be made under
      Rule 8.1 unless:

      8.2.1 the Board shall have invited every such Participant to give an
            indication as to whether or not he approves the alteration; and

      8.2.2 the alteration is approved by a majority of those Participants who
            have given such an indication.

9.    MISCELLANEOUS

9.1   The rights and obligations of any individual under the terms of his office
      or employment with any Group Member shall not be affected by his
      participation in this Scheme or any right which he may have to participate
      in it, and an individual who participates in it shall waive any and all
      rights to compensation or damages in consequence of the termination of his
      office or employment for any reason whatsoever insofar as those rights
      arise or may arise from his ceasing to have rights under or be entitled to
      exercise any option under this Scheme as a result of such termination.

9.2   In the event of any dispute or disagreement as to the interpretation of
      this Scheme, or as to any question or right arising from or related to
      this Scheme, the decision of the Board shall be final and binding upon all
      persons.

9.3   Any notice or other communication under or in connection with this Scheme
      may be given either:

      9.3.1 by personal delivery or by sending the same by post, in the case of
            a company to its registered office, and in the case of an individual
            to his last known address, or, where he is a director or employee of
            a Group Member, either to his last known address or to the address
            of the place of business at which he

<PAGE>

            performs the whole or substantially the whole of the duties of his
            office or employment; or

      9.3.2 in an electronic communication to an address for the time being
            notified for that purpose to the person giving the notice.

9.4   This Scheme and all options granted under it shall be governed by and
      construed in accordance with Bermudan law.

                                                             CLIFFORD CHANCE
                                               LIMITED LIABILITY PARTNERSHIP
                                                       200 Aldersgate Street
                                                             London EC1A 4JJ