Sec Form 4 Filing - WITTMAN VANESSA AMES @ MARSH & MCLENNAN COMPANIES, INC. - 2012-03-06

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 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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1. Name and Address of Reporting Person WITTMAN VANESSA AMES 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) EVP & Chief Financial Officer (Last) (First) (Middle) 1166 AVENUE OF THE AMERICAS 3. Date of Earliest Transaction (MM/DD/YY) 03/06/2012 (Street) NEW YORK, NY10036 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 03/06/2012 M 95,098 A $ 31.3444 117,412 D Common Stock 03/06/2012 S 95,098 D $ 31.3444 22,314 D Common Stock 03/06/2012 M 179,689 A $ 31.5 202,003 D Common Stock 03/06/2012 S 179,689 D $ 31.5 22,314 D Common Stock 03/07/2012 M 13,610 A $ 31.5 35,924 D Common Stock 03/07/2012 S 13,610 D $ 31.5 22,314 D

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Stock Options (Right to Buy) $ 19.045 03/06/2012 M 95,098 ( 1 ) 02/22/2019 Common Stock 95,098 $ 0 81,700 D Stock Options (Right to Buy) $ 22.705 03/06/2012 M 179,689 ( 2 ) 02/21/2020 Common Stock 179,689 $ 0 206,909 D Stock Options (Right to Buy) $ 22.705 03/07/2012 M 13,610 ( 2 ) 02/21/2020 Common Stock 13,610 $ 0 193,299 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other WITTMAN VANESSA AMES 1166 AVENUE OF THE AMERICAS NEW YORK, NY10036 EVP & Chief Financial Officer Signatures /s/ Lucy Fato, Attorney-in-Fact 03/08/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These options were granted on February 23, 2009 and vest in four equal annual installments beginning on the first anniversary of the grant date. The first three installments vested and became exercisable on February 23, 2010, February 23, 2011 and February 23, 2012. The remaining installment vests on February 23, 2013. ( 2 )These options were granted on February 22, 2010 and vest in four equal annual installments beginning on the first anniversary of the grant date. The first two installments vested and became exercisable on February 22, 2011 and February 21, 2012. The second two installments vest on February 22, 2013 and February 22, 2014.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

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