SEC Form 4

FORM 4		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 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* SIMMONS HAROLD C (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol KRONOS WORLDWIDE INC [ KRO ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner X Officer (give title below) Other (specify below) Chairman of the Board
	3. Date of Earliest Transaction (Month/Day/Year) 05/13/2011
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

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 $0.01 par value	05/13/2011		J(1)		11,587(2)	A	$53.7347(2)	98,254	I	by TFMC(3)
Common Stock $0.01 par value	05/13/2011		J(1)		82,105(4)	A	$54.8204(4)	180,459	I	by TFMC(3)
Common Stock $0.01 par value	05/13/2011		J(1)		6,308(5)	A	$55.3305(5)	186,667	I	by TFMC(3)
Common Stock $0.01 par value								259,220	D
Common Stock $0.01 par value								28,995,021	I	by Valhi(6)
Common Stock $0.01 par value								17,609,635	I	by NL(7)
Common Stock $0.01 par value								54,856	I	by Spouse(8)
Common Stock $0.01 par value								2,686	I	by Contran(9)

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 Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person* SIMMONS HAROLD C (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner X Officer (give title below) Other (specify below) Chairman of the Board

1. Name and Address of Reporting Person* CONTRAN CORP (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* VALHI INC /DE/ (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* VALHI HOLDING CO (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* DIXIE RICE AGRICULTURE CORP INC (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* TITANIUM METALS CORP (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* TIMET FINANCE MANAGEMENT CO (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* NL INDUSTRIES INC (Last) (First) (Middle) 5430 LBJ FREEWAY, SUITE 1700 (Street) DALLAS TX 75240 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Open market purchase by TIMET Finance Management Company. See the Additional Information filed as Exhibit 99 to this statement for a description of the relationships among the persons joining in this filing.

2. The price reported in Column 4 is a weighted average price. These acquisitions involved 77 purchases at prices ranging from $53.20 to $54.17 per share. The reporting persons undertake to provide to the issuer, any security holder of the issuer or the U.S. Security and Exchange Commission, upon request, the full information regarding these purchases.

3. Directly held by TIMET Finance Management Company. See the Additional Information filed as Exhibit 99 to this statement for a description of the relationships among the persons joining in this filing.

4. The price reported in Column 4 is a weighted average price. These acquisitions involved 333 purchases at prices ranging from $54.25 to $55.24 per share. The reporting persons undertake to provide to the issuer, any security holder of the issuer or the U.S. Security and Exchange Commission, upon request, the full information regarding these purchases.

5. The price reported in Column 4 is a weighted average price. These acquisitions involved 45 purchases at prices ranging from $55.26 to $55.49 per share. The reporting persons undertake to provide to the issuer, any security holder of the issuer or the U.S. Security and Exchange Commission, upon request, the full information regarding these purchases.

6. Directly held by Valhi, Inc. See the Additional Information filed as Exhibit 99 to this statement for a description of the relationships among the persons joining in this filing.

7. Directly held by NL Industries, Inc. See the Additional Information filed as Exhibit 99 to this statement for a description of the relationship among the persons joining in this filing.

8. Directly held by the reporting person's wife. Mr. Simmons disclaims beneficial ownership of any shares of the issuer's common stock that his wife holds. See the Additional Information filed as Exhibit 99 to this statement for a description of the relationships among the persons joining in this filing.

9. Directly held by Contran Corporation. See the Additional Information filed as Exhibit 99 to this statement for a description of the relationship among the persons joining in this filing.

Remarks:

Exhibit Index Exhibit 99 - Additional Information

	A. Andrew R. Louis. Attorney-in-fact, for Harold C. Simmons	05/16/2011
	A. Andrew R. Louis. Secretary, for Contran Corporation	05/16/2011
	A. Andrew R. Louis. Secretary, for Valhi, Inc.	05/16/2011
	A. Andrew R. Louis. Secretary, for Valhi Holding Corporation	05/16/2011
	A. Andrew R. Louis. Secretary, for Dixie Rice Agricultural Corporation, Inc.	05/16/2011
	A. Andrew R. Louis. Assistant Secretary, for Titanium Metals Corporation	05/16/2011
	A. Andrew R. Louis. Secretary, for NL Industries, Inc.	05/16/2011
	Gregory M. Swalwell. Vice President, for TIMET Finance Management Company	05/16/2011
	** Signature of Reporting Person	Date
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