<PAGE>
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 12, 2001
                                                      REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                            ------------------------

                                    FORM S-8

                             REGISTRATION STATEMENT

                                     UNDER

                           THE SECURITIES ACT OF 1933

                            ------------------------

                         WILLIS GROUP HOLDINGS LIMITED

             (Exact name of Registrant as specified in its charter)

<TABLE>
<S>                           <C>
          BERMUDA                              NONE
(State or other jurisdiction  (I.R.S. Employer Identification Number)
    of incorporation or
       organization)
</TABLE>

                               TEN TRINITY SQUARE
                                LONDON EC3P 3AX
                                    ENGLAND
                             (011) 44-20-7488-8111

   (Address, including zip code, of Registrant's principal executive office)

 WILLIS GROUP HOLDINGS LIMITED NORTH AMERICA 2001 EMPLOYEE STOCK PURCHASE PLAN
                            (Full title of the Plan)

                                MARY E. CAIAZZO
                           WILLIS NORTH AMERICA INC.
                                P.O. BOX 305026
                            NASHVILLE, TN 37230-5026
                                      USA
                                 (615) 872-3006
 (Name, address, including zip code, and telephone number, including area code,
                       of Registrant's agent for service)

                                   COPIES TO:
                              EDWARD P. TOLLEY III
                           SIMPSON THACHER & BARTLETT
                              425 LEXINGTON AVENUE
                         NEW YORK, NEW YORK 10017-3954
                                 (212) 455-2000

                        CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                                                PROPOSED             PROPOSED
                                                                 MAXIMUM              MAXIMUM             AMOUNT OF
                                         AMOUNT TO BE        OFFERING PRICE          AGGREGATE          REGISTRATION
TITLE OF SECURITIES TO BE REGISTERED      REGISTERED          PER SHARE(1)        OFFERING PRICE             FEE
<S>                                   <C>                  <C>                  <C>                  <C>
Common Stock, $0.000115 par value
  per share......................      1,000,000 shares          $13.50             $13,500,000            $3,375
</TABLE>

(1) Estimated solely for the purpose of calculating the registration fee
    pursuant to Rules 457(h)(1) and 457(c) under the Securities Act of 1933, as
    amended.

In addition, pursuant to Rule 416(c) under the Securities Act of 1933, this
registration statement also covers an indeterminate amount of interests to be
offered or sold pursuant to the benefit plan described herein.

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>
                                    PART II
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

    The following documents filed by Willis Group Holdings Limited (the
"Company" or "Registrant") with the Securities and Exchange Commission (the
"Commission") are hereby incorporated by reference in this Registration
Statement.

    (a) The Registrant's Prospectus filed on June 12, 2001 pursuant to
Rule 424(b) of the Securities Act of 1933, as amended (the "Securities Act"),
which contains audited financial statements for the Registrant's latest fiscal
year for which such statements have been filed.

    (b) None.

    (c) The description of the Registrant's capital stock contained in the
Registrant's Registration Statement on Form 8-A filed with the Commission under
Section 12 of the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), on May 21, 2001, including any amendment or report filed for the purpose
of updating such description.

    All documents filed by the Company pursuant to Sections 13(a), 13(c), 14 or
15(d) of the Exchange Act after the date of this Registration Statement and
prior to the filing of a post-effective amendment to this Registration Statement
indicating that all securities offered have been sold or which deregisters all
securities then remaining unsold, shall be deemed to be incorporated by
reference into this Registration Statement and to be a part hereof from the date
of filing of such documents. Any statement contained in a document incorporated
or deemed to be incorporated by reference herein shall be deemed to be modified
or superseded for purposes of this Registration Statement to the extent that a
statement contained herein or in any other subsequently filed document which
also is or is deemed to be incorporated by reference herein modifies or
supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
Registration Statement.

ITEM 4.  DESCRIPTION OF SECURITIES.

    See Item 3(c) above.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

    Not applicable.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

    The Bye-laws of the Registrant provide for indemnification of the
Registrant's officers and directors against all liabilities, loss, damage or
expense incurred or suffered by such party as an officer or director of the
Registrant; provided that such indemnification shall not extend to any matter
which would render it void pursuant to the Companies Act of 1981 as in effect
from time to time in Bermuda.

    The Companies Act provides that a Bermuda company may indemnify its
directors in respect of any loss arising or liability attaching to them as a
result of any negligence, default, breach of duty or breach of trust of which
they may be guilty. However, the Companies Act also provides that any provision,
whether contained in the company's bye-laws or in a contract or arrangement
between the company and the director, indemnifying a director against any
liability which would attach to him in respect of his fraud or dishonesty will
be void. The directors and officers of the Registrant are covered by directors'
and officers' insurance policies maintained by the Registrant.

                                      II-1
<PAGE>
    Under the Amended and Restated Limited Partnership Agreement of Profit
Sharing (Overseas), Limited Partnership, directors of the Registrant who are
officers, directors, employees, partners, stockholders, members or agents of KKR
1996 Fund (Overseas), Limited Partnership or its affiliates are indemnified by
Profit Sharing (Overseas), Limited Partnership to the fullest extent permitted
by law from and against all liabilities, loss, damage or expense relating to the
performance as a director of the Registrant during the period of time in which
Profit Sharing (Overseas), Limited Partnership holds an interest in the
Registrant; provided that such indemnification shall not cover acts not made in
good faith and not in the best interest of the Profit Sharing (Overseas),
Limited Partnership or constitute malfeasance.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

    None.

ITEM 8.  EXHIBITS.

<TABLE>
    <C>                     <S>
             4.1            Memorandum of Association of the Company (incorporated
                              herein by reference to Exhibit 3.1 to Registration
                              Statement No. 333-60982)

             4.2            Form of Bye-Laws of the Company (incorporated herein by
                              reference to Exhibit 3.2 to Registration Statement
                              No. 333-60982)

             4.3            Willis Group Holdings Limited North America 2001 Employee
                              Stock Purchase Plan (filed herewith)

             5              Opinion of Appleby Spurling & Kempe (filed herewith)

            23.1            Consent of Deloitte & Touche (filed herewith)

            23.2            Consent of Appleby, Spurling & Kempe (Reference is made to
                              Exhibit 5 filed herewith)

            24.1            Power of Attorney (included on signature page to this
                              Registration Statement)
</TABLE>

ITEM 9.  UNDERTAKINGS.

    The Company hereby undertakes:

    (a)(1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this Registration Statement:

        (i) to include any prospectus required by Section 10(a)(3) of the
    Securities Act of 1933 (the "Act");

        (ii) to reflect in the prospectus any facts or events arising after the
    effective date of the registration statement (or the most recent
    post-effective amendment thereof) which, individually or in the aggregate,
    represent a fundamental change in the information set forth in the
    registration statement. Notwithstanding the foregoing, any increase or
    decrease in volume of securities offered (if the total dollar value of
    securities offered would not exceed that which was registered) and any
    deviation from the low or high end of the estimated maximum offering range
    may be reflected in the form of prospectus filed with the Commission
    pursuant to Rule 424(b) if, in the aggregate, the changes in volume and
    price represent no more than 20 percent change in the maximum aggregate
    offering price set forth in the "Calculation of Registration Fee" table in
    the effective registration statement; and

        (iii) to include any material information with respect to the plan of
    distribution not previously disclosed in the registration statement or any
    material change to such information in the registration statement; provided,
    however, that paragraphs (a)(1)(i) and (a)(1)(ii) above do not apply if the
    registration statement is on Form S-3, Form S-8 or Form F-3, and the
    information

                                      II-2
<PAGE>
    required to be included in a post-effective amendment by those paragraphs is
    contained in periodic reports filed by the Company pursuant to Section 13 or
    Section 15(d) of the Exchange Act that are incorporated by reference in this
    post-effective amendment.

    (2) That, for the purpose of determining any liability under the Act, each
such post-effective amendment shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

    (3) To remove from registration by means of a post-effective amendment any
of the securities being registered hereby which remain unsold at the termination
of the offering.

    (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Act, each filing of the registrant's annual
report pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in this registration statement shall be deemed to be a
new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

    (c) Insofar as indemnification for liabilities arising under the Act may be
permitted to directors, officers and controlling persons of the registrant
pursuant to the provisions of the Certificate of Amendment Certificate of
Incorporation of the registrant and the provisions of Delaware law described
under Item 6 above, the registrant has been advised that in the opinion of the
Commission such indemnification is against public policy as expressed in the
Act, and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.

                                      II-3
<PAGE>
                                   SIGNATURES

    Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of London, Country of England on the 12th day of June,
2001.

<TABLE>
<S>                                                    <C>  <C>
                                                       WILLIS GROUP HOLDINGS LIMITED

                                                       By:  /s/ JOSEPH J. PLUMERI
                                                            -----------------------------------------
                                                            Name:  Joseph J. Plumeri
                                                            Title:   Executive Chairman and Director
</TABLE>

                               POWER OF ATTORNEY

    KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below hereby constitutes and appoints Thomas Colraine, Mary E. Caiazzo and
Michael Chitty and each of them, as his true and lawful attorneys-in-fact and
agents, with full power of substitution and re-substitution, for him in his
name, place and stead, in any and all capacity, in connection with this
Registration Statement, including to sign and file in the name and on behalf of
the undersigned as director or officer of the Registrant any and all amendments
or supplements (including any and all stickers and post-effective amendments) to
this Registration Statement, with all exhibits thereto, and other documents in
connection therewith with the Securities and Exchange Commission and any
applicable securities exchange or securities self-regulatory body, granting unto
said attorney-in-fact and agents, and each of them full power and authority to
do and perform each and every act and things requisite or necessary to be done
in and about the premises, as fully to all intents and purposes as he or she
might or could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents or any of them, or their substitutes, may lawfully
do or cause to be done by virtue hereof.

    Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.

<TABLE>
<CAPTION>
                SIGNATURE                                     TITLE                        DATE
                ---------                                     -----                        ----
<C>                                         <S>                                        <C>
          /s/ JOSEPH J. PLUMERI             Executive Chairman and Director            June 12, 2001
    ---------------------------------         (principal executive officer)
            Joseph J. Plumeri

           /s/ THOMAS COLRAINE              Chief Financial Officer (principal         June 12, 2001
    ---------------------------------         accounting officer)
             Thomas Colraine

           /s/ HENRY R. KRAVIS              Director                                   June 12, 2001
    ---------------------------------
             Henry R. Kravis

          /s/ GEORGE R. ROBERTS             Director                                   June 12, 2001
    ---------------------------------
            George R. Roberts

             /s/ PERRY GOLKIN               Director                                   June 12, 2001
    ---------------------------------
               Perry Golkin
</TABLE>

                                      II-4
<PAGE>

<TABLE>
<CAPTION>
                SIGNATURE                                     TITLE                        DATE
                ---------                                     -----                        ----
<C>                                         <S>                                        <C>
            /s/ TODD A. FISHER              Director                                   June 12, 2001
    ---------------------------------
              Todd A. Fisher

           /s/ SCOTT C. NUTTALL             Director                                   June 12, 2001
    ---------------------------------
             Scott C. Nuttall

           /s/ JAMES R. FISHER              Director                                   June 12, 2001
    ---------------------------------
             James R. Fisher

            /s/ PAUL M. HAZEN               Director                                   June 12, 2001
    ---------------------------------
              Paul M. Hazen

           /s/ MARY E. CAIAZZO              Authorized U.S. Representative             June 12, 2001
    ---------------------------------
             Mary E. Caiazzo
</TABLE>

                                      II-5
<PAGE>
    THE PLAN.  Pursuant to the requirements of the Securities Act of 1933, as
amended, the administrators of the Willis Group Holdings Limited North America
2001 Employee Stock Purchase Plan have duly caused this Registration Statement
to be signed on its behalf by the undersigned, thereunto duly authorized as of
the 12th day of June, 2001.

WILLIS GROUP HOLDINGS LIMITED NORTH
AMERICA 2001 EMPLOYEE STOCK PURCHASE PLAN

<TABLE>
<S>  <C>
By:                  /s/ JOSEPH J. PLUMERI
          -------------------------------------------
                       Joseph J. Plumeri
                         ADMINISTRATOR

By:                   /s/ HENRY R. KRAVIS
          -------------------------------------------
                        Henry R. Kravis
                         ADMINISTRATOR

By:                  /s/ GEORGE R. ROBERTS
          -------------------------------------------
                       George R. Roberts
                         ADMINISTRATOR

By:                    /s/ PERRY GOLKIN
          -------------------------------------------
                         Perry Golkin
                         ADMINISTRATOR

By:                   /s/ TODD A. FISHER
          -------------------------------------------
                        Todd A. Fisher
                         ADMINISTRATOR

By:                  /s/ SCOTT C. NUTTALL
          -------------------------------------------
                       Scott C. Nuttall
                         ADMINISTRATOR

By:                   /s/ JAMES R. FISHER
          -------------------------------------------
                        James R. Fisher
                         ADMINISTRATOR

By:                    /s/ PAUL M. HAZEN
          -------------------------------------------
                         Paul M. Hazen
                         ADMINISTRATOR
</TABLE>

                                      II-6
<PAGE>
                               INDEX TO EXHIBITS

<TABLE>
<CAPTION>
       EXHIBIT
       NUMBER                                   DESCRIPTION
---------------------   ------------------------------------------------------------
<S>                     <C>
 4.1                    Memorandum of Association of the Company (incorporated
                        herein by reference to Exhibit 3.1 to Registration No.
                        333-60982)

 4.2                    Form of Bye-Laws of the Company (incorporated herein by
                        reference to Exhibit 3.2 to Registration Statement No.
                        333-60982)

 4.3                    Willis Group Holdings Limited North America 2001 Employee
                        Stock Purchase Plan (filed herewith)

 5                      Opinion of Appleby Spurling & Kempe (filed herewith)

 23.1                   Consent of Deloitte & Touche (filed herewith)

 23.2                   Consent of Appleby Spurling & Kempe (Reference is made to
                        Exhibit 5 filed herewith)

 24                     Power of Attorney (included on signature page to this
                        Registration Statement)
</TABLE>
[{"type": "S-8", "sequence": "1", "filename": "a2051406zs-8.txt", "description": "S-8", "secsgml_size_bytes": 21242}]
{"company-data": {"conformed-name": "WILLIS GROUP HOLDINGS LTD", "cik": "0001140536", "assigned-sic": "6411", "irs-number": "000000000", "state-of-incorporation": "D0", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-62780", "film-number": "1658973"}, "business-address": {"street1": "TEN TRINITY SQUARE", "city": "LONDON ENGLAND", "state": "X0", "zip": "00000", "phone": "0114402074"}, "mail-address": {"street1": "TEN TRINITY SQUARE", "city": "LONDON ENGLAND", "state": "X0", "zip": "00000"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 12, 2001
                                                      REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                            ------------------------

                                    FORM S-8

                             REGISTRATION STATEMENT

                                     UNDER

                           THE SECURITIES ACT OF 1933

                            ------------------------

                         WILLIS GROUP HOLDINGS LIMITED

             (Exact name of Registrant as specified in its charter)
BERMUDA                              NONE
(State or other jurisdiction  (I.R.S. Employer Identification Number)
    of incorporation or
       organization)
TEN TRINITY SQUARE
                                LONDON EC3P 3AX
                                    ENGLAND
                             (011) 44-20-7488-8111

   (Address, including zip code, of Registrant's principal executive office)

 WILLIS GROUP HOLDINGS LIMITED NORTH AMERICA 2001 EMPLOYEE STOCK PURCHASE PLAN
                            (Full title of the Plan)

                                MARY E. CAIAZZO
                           WILLIS NORTH AMERICA INC.
                                P.O. BOX 305026
                            NASHVILLE, TN 37230-5026
                                      USA
                                 (615) 872-3006
 (Name, address, including zip code, and telephone number, including area code,
                       of Registrant's agent for service)

                                   COPIES TO:
                              EDWARD P. TOLLEY III
                           SIMPSON THACHER & BARTLETT
                              425 LEXINGTON AVENUE
                         NEW YORK, NEW YORK 10017-3954
                                 (212) 455-2000

                        CALCULATION OF REGISTRATION FEE
PROPOSED             PROPOSED
                                                                 MAXIMUM              MAXIMUM             AMOUNT OF
                                         AMOUNT TO BE        OFFERING PRICE          AGGREGATE          REGISTRATION
TITLE OF SECURITIES TO BE REGISTERED      REGISTERED          PER SHARE(1)        OFFERING PRICE             FEE
Common Stock, $0.000115 par value
  per share......................      1,000,000 shares          $13.50             $13,500,000            $3,375
(1) Estimated solely for the purpose of calculating the registration fee
    pursuant to Rules 457(h)(1) and 457(c) under the Securities Act of 1933, as
    amended.

In addition, pursuant to Rule 416(c) under the Securities Act of 1933, this
registration statement also covers an indeterminate amount of interests to be
offered or sold pursuant to the benefit plan described herein.

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
PART II
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

    The following documents filed by Willis Group Holdings Limited (the
"Company" or "Registrant") with the Securities and Exchange Commission (the
"Commission") are hereby incorporated by reference in this Registration
Statement.

    (a) The Registrant's Prospectus filed on June 12, 2001 pursuant to
Rule 424(b) of the Securities Act of 1933, as amended (the "Securities Act"),
which contains audited financial statements for the Registrant's latest fiscal
year for which such statements have been filed.

    (b) None.

    (c) The description of the Registrant's capital stock contained in the
Registrant's Registration Statement on Form 8-A filed with the Commission under
Section 12 of the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), on May 21, 2001, including any amendment or report filed for the purpose
of updating such description.

    All documents filed by the Company pursuant to Sections 13(a), 13(c), 14 or
15(d) of the Exchange Act after the date of this Registration Statement and
prior to the filing of a post-effective amendment to this Registration Statement
indicating that all securities offered have been sold or which deregisters all
securities then remaining unsold, shall be deemed to be incorporated by
reference into this Registration Statement and to be a part hereof from the date
of filing of such documents. Any statement contained in a document incorporated
or deemed to be incorporated by reference herein shall be deemed to be modified
or superseded for purposes of this Registration Statement to the extent that a
statement contained herein or in any other subsequently filed document which
also is or is deemed to be incorporated by reference herein modifies or
supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
Registration Statement.

ITEM 4.  DESCRIPTION OF SECURITIES.

    See Item 3(c) above.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

    Not applicable.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

    The Bye-laws of the Registrant provide for indemnification of the
Registrant's officers and directors against all liabilities, loss, damage or
expense incurred or suffered by such party as an officer or director of the
Registrant; provided that such indemnification shall not extend to any matter
which would render it void pursuant to the Companies Act of 1981 as in effect
from time to time in Bermuda.

    The Companies Act provides that a Bermuda company may indemnify its
directors in respect of any loss arising or liability attaching to them as a
result of any negligence, default, breach of duty or breach of trust of which
they may be guilty. However, the Companies Act also provides that any provision,
whether contained in the company's bye-laws or in a contract or arrangement
between the company and the director, indemnifying a director against any
liability which would attach to him in respect of his fraud or dishonesty will
be void. The directors and officers of the Registrant are covered by directors'
and officers' insurance policies maintained by the Registrant.

                                      II-1
Under the Amended and Restated Limited Partnership Agreement of Profit
Sharing (Overseas), Limited Partnership, directors of the Registrant who are
officers, directors, employees, partners, stockholders, members or agents of KKR
1996 Fund (Overseas), Limited Partnership or its affiliates are indemnified by
Profit Sharing (Overseas), Limited Partnership to the fullest extent permitted
by law from and against all liabilities, loss, damage or expense relating to the
performance as a director of the Registrant during the period of time in which
Profit Sharing (Overseas), Limited Partnership holds an interest in the
Registrant; provided that such indemnification shall not cover acts not made in
good faith and not in the best interest of the Profit Sharing (Overseas),
Limited Partnership or constitute malfeasance.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

    None.

ITEM 8.  EXHIBITS.
4.1            Memorandum of Association of the Company (incorporated
                              herein by reference to Exhibit 3.1 to Registration
                              Statement No. 333-60982)

             4.2            Form of Bye-Laws of the Company (incorporated herein by
                              reference to Exhibit 3.2 to Registration Statement
                              No. 333-60982)

             4.3            Willis Group Holdings Limited North America 2001 Employee
                              Stock Purchase Plan (filed herewith)

             5              Opinion of Appleby Spurling & Kempe (filed herewith)

            23.1            Consent of Deloitte & Touche (filed herewith)

            23.2            Consent of Appleby, Spurling & Kempe (Reference is made to
                              Exhibit 5 filed herewith)

            24.1            Power of Attorney (included on signature page to this
                              Registration Statement)
ITEM 9.  UNDERTAKINGS.

    The Company hereby undertakes:

    (a)(1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this Registration Statement:

        (i) to include any prospectus required by Section 10(a)(3) of the
    Securities Act of 1933 (the "Act");

        (ii) to reflect in the prospectus any facts or events arising after the
    effective date of the registration statement (or the most recent
    post-effective amendment thereof) which, individually or in the aggregate,
    represent a fundamental change in the information set forth in the
    registration statement. Notwithstanding the foregoing, any increase or
    decrease in volume of securities offered (if the total dollar value of
    securities offered would not exceed that which was registered) and any
    deviation from the low or high end of the estimated maximum offering range
    may be reflected in the form of prospectus filed with the Commission
    pursuant to Rule 424(b) if, in the aggregate, the changes in volume and
    price represent no more than 20 percent change in the maximum aggregate
    offering price set forth in the "Calculation of Registration Fee" table in
    the effective registration statement; and

        (iii) to include any material information with respect to the plan of
    distribution not previously disclosed in the registration statement or any
    material change to such information in the registration statement; provided,
    however, that paragraphs (a)(1)(i) and (a)(1)(ii) above do not apply if the
    registration statement is on Form S-3, Form S-8 or Form F-3, and the
    information

                                      II-2
required to be included in a post-effective amendment by those paragraphs is
    contained in periodic reports filed by the Company pursuant to Section 13 or
    Section 15(d) of the Exchange Act that are incorporated by reference in this
    post-effective amendment.

    (2) That, for the purpose of determining any liability under the Act, each
such post-effective amendment shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

    (3) To remove from registration by means of a post-effective amendment any
of the securities being registered hereby which remain unsold at the termination
of the offering.

    (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Act, each filing of the registrant's annual
report pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in this registration statement shall be deemed to be a
new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

    (c) Insofar as indemnification for liabilities arising under the Act may be
permitted to directors, officers and controlling persons of the registrant
pursuant to the provisions of the Certificate of Amendment Certificate of
Incorporation of the registrant and the provisions of Delaware law described
under Item 6 above, the registrant has been advised that in the opinion of the
Commission such indemnification is against public policy as expressed in the
Act, and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.

                                      II-3
SIGNATURES

    Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of London, Country of England on the 12th day of June,
2001.
WILLIS GROUP HOLDINGS LIMITED

                                                       By:  /s/ JOSEPH J. PLUMERI
                                                            -----------------------------------------
                                                            Name:  Joseph J. Plumeri
                                                            Title:   Executive Chairman and Director
POWER OF ATTORNEY

    KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below hereby constitutes and appoints Thomas Colraine, Mary E. Caiazzo and
Michael Chitty and each of them, as his true and lawful attorneys-in-fact and
agents, with full power of substitution and re-substitution, for him in his
name, place and stead, in any and all capacity, in connection with this
Registration Statement, including to sign and file in the name and on behalf of
the undersigned as director or officer of the Registrant any and all amendments
or supplements (including any and all stickers and post-effective amendments) to
this Registration Statement, with all exhibits thereto, and other documents in
connection therewith with the Securities and Exchange Commission and any
applicable securities exchange or securities self-regulatory body, granting unto
said attorney-in-fact and agents, and each of them full power and authority to
do and perform each and every act and things requisite or necessary to be done
in and about the premises, as fully to all intents and purposes as he or she
might or could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents or any of them, or their substitutes, may lawfully
do or cause to be done by virtue hereof.

    Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.
SIGNATURE                                     TITLE                        DATE
                ---------                                     -----                        ----
/s/ JOSEPH J. PLUMERI             Executive Chairman and Director            June 12, 2001
    ---------------------------------         (principal executive officer)
            Joseph J. Plumeri

           /s/ THOMAS COLRAINE              Chief Financial Officer (principal         June 12, 2001
    ---------------------------------         accounting officer)
             Thomas Colraine

           /s/ HENRY R. KRAVIS              Director                                   June 12, 2001
    ---------------------------------
             Henry R. Kravis

          /s/ GEORGE R. ROBERTS             Director                                   June 12, 2001
    ---------------------------------
            George R. Roberts

             /s/ PERRY GOLKIN               Director                                   June 12, 2001
    ---------------------------------
               Perry Golkin
II-4
SIGNATURE                                     TITLE                        DATE
                ---------                                     -----                        ----
/s/ TODD A. FISHER              Director                                   June 12, 2001
    ---------------------------------
              Todd A. Fisher

           /s/ SCOTT C. NUTTALL             Director                                   June 12, 2001
    ---------------------------------
             Scott C. Nuttall

           /s/ JAMES R. FISHER              Director                                   June 12, 2001
    ---------------------------------
             James R. Fisher

            /s/ PAUL M. HAZEN               Director                                   June 12, 2001
    ---------------------------------
              Paul M. Hazen

           /s/ MARY E. CAIAZZO              Authorized U.S. Representative             June 12, 2001
    ---------------------------------
             Mary E. Caiazzo
II-5
THE PLAN.  Pursuant to the requirements of the Securities Act of 1933, as
amended, the administrators of the Willis Group Holdings Limited North America
2001 Employee Stock Purchase Plan have duly caused this Registration Statement
to be signed on its behalf by the undersigned, thereunto duly authorized as of
the 12th day of June, 2001.

WILLIS GROUP HOLDINGS LIMITED NORTH
AMERICA 2001 EMPLOYEE STOCK PURCHASE PLAN
By:                  /s/ JOSEPH J. PLUMERI
          -------------------------------------------
                       Joseph J. Plumeri
                         ADMINISTRATOR

By:                   /s/ HENRY R. KRAVIS
          -------------------------------------------
                        Henry R. Kravis
                         ADMINISTRATOR

By:                  /s/ GEORGE R. ROBERTS
          -------------------------------------------
                       George R. Roberts
                         ADMINISTRATOR

By:                    /s/ PERRY GOLKIN
          -------------------------------------------
                         Perry Golkin
                         ADMINISTRATOR

By:                   /s/ TODD A. FISHER
          -------------------------------------------
                        Todd A. Fisher
                         ADMINISTRATOR

By:                  /s/ SCOTT C. NUTTALL
          -------------------------------------------
                       Scott C. Nuttall
                         ADMINISTRATOR

By:                   /s/ JAMES R. FISHER
          -------------------------------------------
                        James R. Fisher
                         ADMINISTRATOR

By:                    /s/ PAUL M. HAZEN
          -------------------------------------------
                         Paul M. Hazen
                         ADMINISTRATOR
II-6
INDEX TO EXHIBITS
EXHIBIT
       NUMBER                                   DESCRIPTION
---------------------   ------------------------------------------------------------
4.1                    Memorandum of Association of the Company (incorporated
                        herein by reference to Exhibit 3.1 to Registration No.
                        333-60982)

 4.2                    Form of Bye-Laws of the Company (incorporated herein by
                        reference to Exhibit 3.2 to Registration Statement No.
                        333-60982)

 4.3                    Willis Group Holdings Limited North America 2001 Employee
                        Stock Purchase Plan (filed herewith)

 5                      Opinion of Appleby Spurling & Kempe (filed herewith)

 23.1                   Consent of Deloitte & Touche (filed herewith)

 23.2                   Consent of Appleby Spurling & Kempe (Reference is made to
                        Exhibit 5 filed herewith)

 24                     Power of Attorney (included on signature page to this
                        Registration Statement)