Unassociated Document

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

(Rule 13d-102)

Information Statement Pursuant to Rules 13d-1 and 13d-2

Under the Securities Exchange Act of 1934

(Amendment No. )*

OM Group, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

670872100

(CUSIP Number)

July 24, 2008

Date of Event Which Requires Filing of the Statement

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

o	Rule 13d-1(b)
x	Rule 13d-1(c)
o	Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

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Cusip No. 670872100

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Page 2 of 17 Pages

1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Investment Group, L.L.C.
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited liability company
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽¹⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON OO; HC

(1)	Based on 30,537,345 outstanding shares of the Common Stock of Issuer, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2008, as filed with the Securities and Exchange Commission on May 8, 2008.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Investment Group II, L.L.C.
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited liability company
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽²⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON OO; HC

(2) See footnote 1 above.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Limited Partnership
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited partnership
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽³⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON PN; HC

(3) See footnote 1 above.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Kenneth Griffin
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION U.S. Citizen
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽⁴⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON IN; HC

(4) See footnote 1 above.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Holdings I LP
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited partnership
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽⁵⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON PN; HC

(5) See footnote 1 above.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Holdings II LP
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited partnership
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽⁶⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON PN; HC

(6) See footnote 1 above.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Advisors LLC
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited liability company
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽⁷⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON OO; HC

(7) See footnote 1 above.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Equity Fund Ltd.
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands company
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽⁸⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON CO

(8) See footnote 1 above.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Derivatives Group LLC
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited liability company
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽⁹⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON OO; BD

(9) See footnote 1 above.

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1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Derivatives Trading Ltd.
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands company
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,615,916 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 5.3%⁽¹⁰⁾ as of the date of this filing
12.	TYPE OF REPORTING PERSON CO

(10) See footnote 1 above.

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Item 1(a) Name of Issuer: OM Group, Inc.

1(b) Address of Issuer’s Principal Executive Offices:

127 Public Square

1500 Key Tower

Cleveland, Ohio 44114-1221

Item 2(a) Name of Person Filing⁽¹¹⁾

Item 2(b) Address of Principal Business Office

Item 2(c) Citizenship

	Citadel Investment Group, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited liability company

	Citadel Investment Group II, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited liability company

	Citadel Limited Partnership
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited partnership

	Kenneth Griffin
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	U.S. Citizen

	Citadel Holdings I LP
	c/o Citadel Investment Group II, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited partnership

(11) Citadel Holdings Ltd., a Cayman Islands company (“CH”), is majority owned by Citadel Kensington Global Strategies Fund Ltd., a Bermuda company (“CKGSF”). Citadel Equity Fund Ltd. (“CEF”) is a subsidiary of CH. CKGSF and CH do not have control over the voting or disposition of securities held by CEF. Citadel Derivatives Group LLC (“CDG”) is majority owned by Citadel Derivatives Group Investors, LLC, a Delaware limited liability company (“CDGI”). CDGI does not have control over the voting or disposition of securities held by CDG. Citadel Derivatives Trading Ltd. (“CDT”) is majority owned by CLP Holdings LLC, a Delaware limited liability company (“CLPH”). CLPH does not have control over the voting or disposition of securities held by CDT.

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	Citadel Holdings II LP
	c/o Citadel Investment Group II, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited partnership

	Citadel Advisors LLC
	c/o Citadel Investment Group II, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited liability company

	Citadel Equity Fund Ltd.
	c/o Citadel Investment Group, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Cayman Islands company

	Citadel Derivatives Group LLC
	c/o Citadel Investment Group II, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited liability company

	Citadel Derivatives Trading Ltd.
	c/o Citadel Investment Group II, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Cayman Islands company

2(d) Title of Class of Securities:

Common Stock, par value $0.01 per share

2(e) CUSIP Number: 670872100

Item 3 If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b) or (c), check whether the person filing is a:

(a)

Broker or dealer registered under Section 15 of the Exchange Act;


(b)	o	Bank as defined in Section 3(a)(6) of the Exchange Act;

(c)	o	Insurance company as defined in Section 3(a)(19) of the Exchange Act;

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(d)	o	Investment company registered under Section 8 of the Investment Company Act;

(e)	o	An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

(f)	o	An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);

(g)	o	A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);

(h)	o	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act;

(i)	o	A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act;

(j)	o	Group, in accordance with Rule 13d-1(b)(1)(ii)(J).