UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934

                                (Amendment No. _ )*

                         Willis Group Holdings Limited
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                                (Name of Issuer)

                                 Common Stock
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                         (Title of Class of Securities)

                                  G96655108
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                                 (CUSIP Number)

                               December 31, 2007
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             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

         [X] Rule 13d-1(b)

         [ ] Rule 13d-1(c)

         [ ] Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).





                                  SCHEDULE 13G

CUSIP No. G96655108

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      1.   Names of Reporting Persons.  I.R.S.  Identification Nos. of above
           persons (entities only).
           Invesco Ltd.
                       AIM Funds Management Inc.
                       PowerShares Capital Management LLC
                       PowerShares Capital Mgmt Ireland LTD

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      2.   Check the Appropriate Box if a Member of a Group (see
           Instructions)
           (a)
           (b)

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      3.   SEC Use Only  ____________________________________________

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      4.   Citizenship or Place of Organization
           Invesco Ltd. - Bermuda
                       AIM Funds Management Inc. - Canada
                       PowerShares Capital Management LLC - US
                       PowerShares Capital Mgmt Ireland LTD - Ireland

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                           5.  Sole Voting Power 9,827,171: Such shares are
                               held by the following entities in the respective
                               amounts listed:

                                AIM Funds Management Inc. - 9,819,676
                                PowerShares Capital Management LLC - 7,461
                                PowerShares Capital Mgmt Ireland LTD - 34

Number of Shares       ---------------------------------------------------------
Beneficially Owned
by Each Reporting          6.  Shared Voting Power       -0-
Person With
                       ---------------------------------------------------------

                           7.  Sole Dispositive Power 9,827,171: Such shares
                               are held by the following entities in the
                               respective amounts listed:

                                 AIM Funds Management Inc. - 9,819,676
                                 PowerShares Capital Management LLC - 7,461
                                 PowerShares Capital Mgmt Ireland LTD - 34

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

                           8.  Shared Dispositive Power       -0-

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          9.   Aggregate Amount Beneficially Owned by Each Reporting Person:
               9,827,171

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          10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares
               (See Instructions) N/A

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          11.  Percent of Class Represented by Amount in Row (9)   6.88%

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          12.  Type of Reporting Person (See Instructions)
               IA, HC. See Items 2 and 3 of this statement.




                                  SCHEDULE 13G

Item 1(a)         Name of Issuer:

                      Willis Group Holdings LTD

Item 1(b)         Address of Issuer's Principal Executive Offices:

                           Ten Trinity Square
                           London, EC3P 3AX
                           United Kingdom

Item 2(a)         Name of Person Filing:

                  Invesco Ltd.

                  In accordance with Securities and Exchange Commission Release
                  No. 34-39538 (January 12, 1998), this statement on Schedule
                  13G or amendment thereto is being filed by Invesco Ltd.
                  ("Invesco"), a Bermuda Company, on behalf of itself and its
                  subsidiaries listed in Item 4 of the cover of this statement.
                  Invesco through such subsidiaries provides investment
                  management services to institutional and individual investors
                  worldwide.

                  Executive officers and directors of Invesco or its
                  subsidiaries may beneficially own shares of the securities of
                  the issuer to which this statement relates (the "Shares"), and
                  such Shares are not reported in this statement. Invesco and
                  its subsidiaries disclaim beneficial ownership of Shares
                  beneficially owned by any of their executive officers and
                  directors. Each of Invesco's direct and indirect subsidiaries
                  also disclaim beneficial ownership of Shares beneficially
                  owned by Invesco and any other subsidiary.

Item 2(b)         Address of Principal Business Office:

                  1360 Peachtree Street NE
                  Atlanta, GA 30309
                  United States

Item 2(c)         Citizenship:

                  See the response to Item 2(a) of this statement.

Item 2(d)         Title of Class of Securities:

                  Common Stock, $.00011 par value per share

Item 2(e)         CUSIP Number:

                  G96655108

Item 3            If this statement is filed pursuant to ss240.13d-1(b) or
                  240.13d-2(b) or (c), check whether the person filing is a:

          (e) [x] An investment adviser in accordance with section
                  240.13d-1(b)(1)(ii)(E)

          (g) [x] A parent holding company or control person in accordance with
                  section 240.13d-1(b)(1)(ii)(G)

                  As noted in Item 2 above, Invesco is making this filing on
                  behalf of its subsidiaries listed herein. Each of these
                  entities is either an investment adviser registered with the
                  United States Securities and Exchange Commission under
                  Section 203 of the Investment Advisers Act of 1940,
                  as amended, or under similar laws of other jurisdictions.
                  Invesco is a holding company.



Item 4       Ownership:

             Please see responses to Items 5-8 on the cover of this
             statement, which are incorporated herein by reference.

Item 5       Ownership of Five Percent or Less of a Class:

             If this statement is being filed to report the fact that as of
             the date hereof the reporting person has ceased to be the
             beneficial owner of more than five percent of the class of
             securities, check the following

             [ ]

Item 6       Ownership of More than Five Percent on Behalf of Another Person:

             N/A

Item 7       Identification and Classification of the Subsidiary Which Acquired
             the Security Being reported on By the Parent Holding Company:

             Please see Item 3 of this statement, which is incorporated herein
             by reference.

Item 8       Identification and Classification of Members of the Group:

             N/A

Item 9       Notice of Dissolution of a Group:

             N/A

Item 10      Certification:

             By signing below I certify that, to the best of my knowledge and
             belief, the securities referred to above were acquired and are
             held in the ordinary course of business and were not acquired and
             are not held for the purpose of or with the effect of changing or
             influencing the control of the issuer of the securities and were
             not acquired and are not held in connection with or as a
             participant in any transaction having that purpose or effect.

             Signature:

             After reasonable inquiry and to the best of my knowledge and
             belief, I certify that the information set forth in this
             statement is true, complete and correct.

                                                    02/09/2008
                                      ------------------------------------------
                                                       Date

                                      Invesco Ltd.

                                      By: /s/ Lisa Brinkley
                                          --------------------------------------
                                      Lisa Brinkley
                                      Global Compliance Director