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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                              --------------------
                                  SCHEDULE TO-C
                                 (RULE 14d-100)
       Tender Offer Statement Pursuant to Section 14(d)(1) or 13(e)(1) of
                       the Securities Exchange Act of 1934

                        Marsh & McLennan Companies, Inc.
                            (Name of Subject Company)

                        Marsh & McLennan Companies, Inc.
                       (Names of Filing Persons - Offeror)

           Options to Purchase Common Stock, par value $1.00 per share
                         (Title of Class of Securities)
                         ------------------------------


              ----------------------------------------------------
                                 Peter J. Beshar
              Senior Vice President, General Counsel and Secretary
                        Marsh & McLennan Companies, Inc.
                           1166 Avenue of the Americas
                          New York, New York 10036-2774
                                 (212) 345-5000
   (Name, Address and Telephone Number of Person Authorized to Receive Notices
                 and Communications on Behalf of Filing Persons)

                                   Copies to:
                            Richard D. Truesdell, Jr.
                              Davis Polk & Wardwell
                              450 Lexington Avenue
                            New York, New York 10017
                            Telephone: (212) 450-4000


                           CALCULATION OF FILING FEE*
        Transaction valuation                     Amount of filing fee
- -------------------------------------- -----------------------------------------

*No filing fee is required because this filing contains only preliminary
communications made before the commencement of a tender offer.

|_| Check the box if any part of the fee is offset as provided by Rule
    0-11(a)(2) and identify the filing with which the offsetting fee was
    previously paid. Identify the previous filing by registration statement
    number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:   ___________________  Filing Party: ___________________
Form or Registration No.: ___________________  Date Filed:   ___________________

|X| Check the box if the filing relates solely to preliminary communications
    made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the
statement relates:
|_| third-party tender offer subject to Rule 14d-1.
|X| issuer tender offer subject to Rule 13e-4.
|_| going-private transaction subject to Rule 13e-3.
|_| amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results
of the tender offer: |_|

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This schedule and attached exhibit relate to a proposal to be considered by stockholders of Marsh & McLennan Companies, Inc. ("MMC") at the 2005 Annual Meeting of Stockholders to be held on May 19, 2005 (the "2005 Annual Meeting"). The proposal concerns amendments to certain employee stock benefit plans that would permit MMC to make an offer to its employee optionholders (other than it's most senior executive officers) to tender certain outstanding stock options in exchange for stock options to purchase a lesser number of shares of MMC common stock. MMC has not commenced the exchange offer referred to in this communication. When the exchange offer is commenced, MMC will provide eligible optionholders with written materials explaining the terms and conditions and timing of the exchange offer. The tender offer materials and the proxy statement for the 2005 Annual Meeting will contain important information for optionholders and stockholders, respectively, and should be read carefully by them prior to tendering or voting. The proxy statement has been filed by MMC with the Securities and Exchange Commission. The tender offer materials will be filed by MMC with the Securities and Exchange Commission. These written materials and other documents may be obtained free of charge from the Securities and Exchange Commission's website at www.sec.gov. MMC stockholders may obtain a written copy of the proxy statement and eligible MMC optionholders may obtain free of charge a written copy of the tender offer statement, when available, by contacting MMC Corporate Development at (212) 345-5475. Item 12. Exhibit. 99.1 Letter to Employees from Michael A. Petrullo, senior vice president and chief administrative officer of Marsh & McLennan Companies, Inc.

SIGNATURE After due 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. /s/ Bart Schwartz ---------------------------------------- (Signature) Bart Schwartz, Deputy General Counsel ---------------------------------------- (Name & Title) April 13, 2005 ---------------------------------------- (Date)

INDEX TO EXHIBITS 99.1 Letter to Employees (filed herewith).


                                                                    Exhibit 99.1



                                                Michael A. Petrullo
[GRAPHIC OMITTED]

                                                Marsh & McLennan Companies, Inc.
                                                1166 Avenue of the Americas
                                                New York, New York 10036
                                                212 345 1436  Fax  212 345 1978
                                                Michael.Petrullo@MMC.com
                                                www.mmc.com




April 13, 2005



To All MMC Optionholders:


On  March 1, 2005, MMC announced  its proposal to offer a stock option  exchange
program for certain outstanding  options held by active employees.  The proposal
is described in detail in the 2005 MMC Proxy Statement.  In short,  options that
are 25% or more "underwater" will be eligible for exchange.  Pending shareholder
approval  at  the  2005  Annual  Meeting,  which  is  being  held on  May 19, we
anticipate  communicating  the specifics of the offer to those active  employees
holding eligible  options within a few days of the meeting.  Holders of eligible
options will receive specific  information on the exchange process, the exchange
timeframe,  the tax  implications of the exchange,  the options eligible for the
exchange  and the  exchange  ratios.  If your  options  do not  qualify  for the
exchange,  you will not  receive  this  information.  In any case,  no action is
required on your part at this time.

The intent of the proposed  exchange is to ensure that outstanding stock options
serve as  motivation  and retention  tools to employees whom the Company and its
shareholders  rely upon to move the Company  forward.  We believe a stock option
exchange program  to replace eligible options on a  value-for-value  basis is in
the interests of optionholders, shareholders and our Company.

To recap, some  key  points  about the stock  option  exchange  proposal  are as
follows:

       o      MMC's most senior executive officers are excluded from the
              exchange program.
       o      Only stock options underwater by 25% or more would be eligible for
              the exchange program. (For example, options with an exercise price
              of $46.14 will be eligible for exchange if the market price of MMC
              stock is $34.605 or less at the selected date.)
       o      Exchange ratios would be set with the intention that optionholders
              receive new stock options that have a value that is equal to 90%
              of the value of the exchanged stock options.
       o      The exercise price of new options will be equal to the fair market
              value of MMC common stock at the time of the exchange.


[GRAPHIC OMITTED] Page 2 April 13, 2005 Thank you for your continuing contributions to our Company's success. Michael A. Petrullo Senior Vice President & Chief Administrative Officer Marsh & McLennan Companies, Inc. MMC has not commenced the exchange offer referred to in this communication. When the exchange offer is commenced, MMC will provide eligible optionholders with written materials explaining the terms and conditions and timing of the exchange offer. The tender offer materials and the proxy statement for the 2005 Annual Meeting will contain important information for optionholders and stockholders, respectively, and should be read carefully by them prior to tendering or voting. The proxy statement has been filed by MMC with the Securities and Exchange Commission. The tender offer materials will be filed by MMC with the Securities and Exchange Commission. These written materials and other documents may be obtained free of charge from the Securities and Exchange Commission's website at www.sec.gov. MMC stockholders may obtain a written copy of the proxy statement and eligible MMC optionholders may obtain free of charge a written copy of the tender offer statement, when available, by contacting MMC Corporate Development at (212) 345-5475.