SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* SOUTHEASTERN ASSET MANAGEMENT INC/TN/ (Last) (First) (Middle) 6410 POPLAR AVENUE SUITE 900 (Street) MEMPHIS TN 38119 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 05/18/2012	3. Issuer Name and Ticker or Trading Symbol MARTIN MARIETTA MATERIALS INC [ MLM ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of 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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	6,205,303	I	Voting and/or investment discretion per investment advisory contracts

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

Remarks:

Southeastern Asset Management, Inc. ("Southeastern") does not have a pecuniary interest in the securities. As a result of a conversion from a Schedule 13G to Schedule 13D filing, Southeastern may now be deemed a "beneficial owner" of more than 10% of the company's common stock for Section 16 purposes under Rule 16a-1(a)(1). As permitted by Rule 16a-1, this Form 3 shall not be deemed an admission that Southeastern is the beneficial owner of more than 10% of the company's common stock for Section 16 purposes.

	/s/ Steven P. McBride, Assistant General Counsel, Southeastern Asset Management, Inc.	05/25/2012
	** Signature of Reporting Person	Date
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 5 (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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