SC 13G/A

NAME OF REPORTING PERSON

CCMP Capital Investors III, L.P.

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

(a) ☐ (b) ☒

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G/A

(Rule 13d-102)

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

Under the Securities Exchange Act of 1934

(Amendment No. 3)*

ECOVYST INC.

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

27923Q 109

(CUSIP Number)

December 31, 2023

(Date of Event Which Requires Filing of this Statement)

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

☐ Rule 13d-1(b)

☐ Rule 13d-1(c)

☒ 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 in 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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*	See Item 4


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*	See Item 4


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*	See Item 4


CUSIP No. 27923Q 109		13G/A		Page 14 of 19 Pages

Item 1(a).

Name of Issuer

Ecovyst Inc. (the “Issuer”)

Item 1(b).

Address of Issuer’s Principal Executive Offices

300 Lindenwood Drive

Valleybrooke Corporate Center

Malvern, Pennsylvania 19355.

Item 2.

(a) Name of Person Filing

This statement is filed by the entities listed below, all of whom together are referred to herein as the “Reporting Persons”:

(i)	CCMP Capital Investors III, L.P. (“CCMP Capital Investors”);

(ii)	CCMP Capital Investors III (Employee), L.P. (“CCMP Employee”);

(iii)

CCMP Capital Investors III (AV-7), L.P. (“CCMP AV-7”);

(iv)	CCMP Capital Investors III (AV-8), L.P. (“CCMP AV-8”);

(v)	CCMP Capital Investors III (AV-9), L.P. (“CCMP AV-9”);

(vi)	CCMP Capital Investors III (AV-10), L.P. (“CCMP AV-10” and, together with CCMP Capital Investors, CCMP Employee, CCMP AV-7, CCMP AV-8, and CCMP AV-9, the “CCMP Capital Funds”);

(vii)

CCMP Capital Associates III, L.P. (“CCMP Capital Associates”);

(viii)

CCMP Capital Associates III GP, LLC (“CCMP Capital Associates GP”);

(ix)	CCMP Capital, LP (“CCMP Capital”);

(x)	CCMP Capital GP, LLC (“CCMP Capital GP”);

(xi)	Quartz Co-Invest, L.P. (“Quartz”); and

(xii)

CCMP Co-Invest III A GP, LLC (“CCMP Co-Invest GP”).

The Reporting Persons have entered into a Joint Filing Agreement, dated February 4, 2022 and incorporated herein by reference to Exhibit A to the Schedule 13G filed by the Reporting Persons with the Securities and Exchange Commission (the “SEC”) with respect to the Issuer on February 9, 2022, pursuant to which the Reporting Persons have agreed to file this statement jointly in accordance with the provisions of Rule 13d-1(k)(1) under the Act.

(b) Address of Principal Business Office or, if none, Residence

All Reporting Persons: c/o CCMP Capital Advisors, LP, 1 Rockefeller Plaza, 16th Floor, New York, NY 10020

(c) Citizenship

All Reporting Persons: Delaware

(d) Title of Class of Securities

Common Stock, par value $0.01 per share (the “Common Stock”)

(e) CUSIP Number

27923Q 109.


CUSIP No. 27923Q 109		13G/A		Page 15 of 19 Pages

Item 3.

If this statement is filed pursuant to §§ 240.13d-1(b), or 240.13d-2(b) or (c), check whether the person filing is a:

☐	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

☐	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

☐	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

☐	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

☐	An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E).

☐	An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F).

☐	A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G).

☐	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813).

☐	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3).

☐	A non-U.S. institution in accordance with §240.13d-1(b)(1)(ii)(J).

☐	Group, in accordance with §240.13d-1(b)(1)(ii)(K).

Item 4.

Ownership

(a) Amount beneficially owned

As of December 31, 2023, the Reporting Persons may be deemed to beneficially own in the aggregate 0 shares of the Issuer’s Common Stock, representing, in the aggregate, approximately 0% of the Issuer’s total Common Stock outstanding.

The general partner of each of the CCMP Capital Funds is CCMP Capital Associates. The general partner of CCMP Capital Associates is CCMP Capital Associates GP. As a result, each of CCMP Capital Associates and CCMP Capital Associates GP may be deemed to share beneficial ownership with respect to the Common Stock held by the CCMP Capital Funds.

The general partner of Quartz is CCMP Co-Invest GP. As a result, CCMP Co-Invest GP may be deemed to share beneficial ownership with respect to the Common Stock held by Quartz.

CCMP Capital Associates GP and CCMP Co-Invest GP are each wholly owned by CCMP Capital.

The general partner of CCMP Capital is CCMP Capital GP. CCMP Capital GP ultimately exercises voting and dispositive power over the securities held by the CCMP Capital Funds and Quartz. As a result, each of CCMP Capital and CCMP Capital GP may be deemed to share beneficial ownership with respect to the Common Stock held by the CCMP Capital Funds and Quartz.

(b) Percent of Class

The responses of the Reporting Persons to Row 11 of each of the cover pages to this Schedule 13G/A are hereby incorporated by reference. The percentages represent the percentage of the Issuer’s Common Stock beneficially owned by the Reporting Persons.

(c) Number of shares as to which such person has:

(i) Sole power to vote or to direct the vote: The responses of the Reporting Persons to Row 5 of each of the cover pages to this Schedule 13G/A are hereby incorporated by reference.

(ii) Shared power to vote or to direct the vote: The responses of the Reporting Persons to Row 6 of each of the cover pages to this Schedule 13G/A are hereby incorporated by reference. See also Item 4(a) above.

(iii) Sole power to dispose or to direct the disposition of: The responses of the Reporting Persons to Row 7 of each of the cover pages to this Schedule 13G/A are hereby incorporated by reference.

(iv) Shared power to dispose or to direct the disposition of: The responses of the Reporting Persons to Row 8 of each of the cover pages to this Schedule 13G/A are hereby incorporated by reference. See also Item 4(a) above.


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Item 5.

Ownership of Five Percent or Less of a Class

Not applicable.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person

Not applicable.

Item 7.

Identification and Classification of the Subsidiary which Acquired the Security Being Reported on by the Parent Holding Company or Control Person:

Not applicable.

Item 8.

Identification and Classification of Members of the Group

Not applicable.

Item 9.

Notice of Dissolution of Group

Not applicable.


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Item 10.

Certification

Not applicable.


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SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, the undersigned certifies that the information set forth in this Statement is true, complete and correct.

Dated: February 12, 2024


CCMP CAPITAL INVESTORS III, L.P.
CCMP CAPITAL INVESTORS III (EMPLOYEE), L.P.
CCMP CAPITAL INVESTORS III (AV-7), L.P.
CCMP CAPITAL INVESTORS III (AV-8), L.P.
CCMP CAPITAL INVESTORS III (AV-9), L.P.
CCMP CAPITAL INVESTORS III (AV-10), L.P.

By: CCMP Capital Associates III, L.P., its general partner

By: CCMP Capital Associates III GP, LLC, its general partner,

By:		/s/ Mark McFadden
		Managing Partner

CCMP CAPITAL ASSOCIATES III, L.P.

By: CCMP Capital Associates III GP, LLC, its general partner

By:		/s/ Mark McFadden
		Managing Partner

CCMP CAPITAL ASSOCIATES III GP, LLC

By:		/s/ Mark McFadden
		Managing Partner

QUARTZ CO-INVEST, L.P.

By: CCMP Co-Invest III A GP, LLC, its general partner

By:		/s/ Mark McFadden
		Managing Partner

CCMP CO-INVEST III A GP, LLC

By:		/s/ Mark McFadden
		Managing Partner


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CCMP CAPITAL, LP

By: CCMP Capital GP, LLC its general partner

By:		/s/ Mark McFadden
		Managing Partner

CCMP CAPITAL GP, LLC

By:		/s/ Mark McFadden
		Managing Partner