Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Zaffino Peter
  2. Issuer Name and Ticker or Trading Symbol
MARSH & MCLENNAN COMPANIES, INC. [MMC]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
President & CEO, Guy Carpenter
(Last)
(First)
(Middle)
1166 AVENUE OF THE AMERICAS
3. Date of Earliest Transaction (Month/Day/Year)
02/12/2010
(Street)

NEW YORK, NY 10036
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 02/12/2010   M(1)   1,409 A $ 0 1,409 D  
Common Stock 02/12/2010   F(1)   477 D $ 21.98 932 D  
Common Stock               1,040.174 (2) I MMC 401(k) Savings & Investment Plan

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Restricted Stock Units (3) 02/12/2010   A(4)   845     (5)   (5) Common Stock 845 $ 0 75,970 D  
Restricted Stock Units (3) 02/12/2010   M(1)     1,409   (5)   (5) Common Stock 1,409 $ 0 74,561 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Zaffino Peter
1166 AVENUE OF THE AMERICAS
NEW YORK, NY 10036
      President & CEO, Guy Carpenter  

Signatures

 /s/ Lucy Fato, Attorney-in-Fact   02/16/2010
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Vesting and distribution to reporting person of 1,409 shares of restricted stock units (including 845 restricted stock units relating to performance based restricted stock units for the performance period 2007-2009 and 564 other restricted stock units) of which 477 shares were withheld by MMC to cover applicable taxes.
(2) Reflects additional shares acquired by the MMC 401(k) Savings & Investment Plan (SIP) Custodian at prevailing market prices. Information reported herein is based on reporting person's Plan Statement as of year end.
(3) The security converts to MMC common stock on a 1-for-1 basis.
(4) These restricted stock units relate to performance based restricted stock units for the performance period 2007-2009, that vested and were distributed on February 12, 2010.
(5) Not Applicable.

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