SC 13G

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13G

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(b),

(c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. )*

CLEARBRIDGE ENERGY MIDSTREAM OPPORTUNITY FUND INC.

(Name of Issuer)

Mandatory Redeemable Preferred Stock

(Title of Class of Securities)

18469P2#6, 18469P3#5, 18469P4#4, 18469#110, 18469#128, 18469#136, 18469#144

(CUSIP Numbers)

November 16, 2018

(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 disclosure 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, 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).

CUSIP Nos. 18469P2#6, 18469P3#5, 18469P4#4,

18469#110, 18469#128, 18469#136, 18469#144

1.	Name of reporting person American International Group, Inc.
2.	Check the appropriate box if a member of a group (a)  ☐        (b)  ☒
3.	SEC use only
4.	Citizenship or place of organization Incorporated under the laws of the State of Delaware
Number of shares beneficially owned by each reporting person with		5.	Sole voting power 0
		6.	Shared voting power 100
		7.	Sole dispositive power 0
		8.	Shared dispositive power 100
9.	Aggregate amount beneficially owned by each reporting person 100
10.	Check box if the aggregate amount in Row (9) excludes certain shares ☐
11.	Percent of class represented by amount in Row (9) 20.83%
12.	Type of reporting person HC

ITEM 1 (a). NAME OF ISSUER:

ClearBridge Energy Midstream Opportunity Fund Inc. (the “Issuer”)

ITEM 1 (b). ADDRESS OF ISSUER’S PRINCIPAL EXECUTIVE OFFICES:

620 Eighth Avenue, 49th Floor

New York, NY 10018

ITEM 2 (a). NAME OF PERSON FILING:

This Schedule 13G is filed by American International Group, Inc. (“AIG”).

ITEM 2 (b). ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:

175 Water Street

New York, NY 10038

ITEM 2 (c). CITIZENSHIP:

Incorporated under the laws of the State of Delaware.

ITEM 2 (d). TITLE OF CLASS OF SECURITIES:

Mandatory Redeemable Preferred Stock

ITEM 2 (e). CUSIP NUMBERS:

18469P2#6 (Series A Mandatory Redeemable Preferred Stock) (the “Series A Preferred Stock”)

18469P3#5 (Series B Mandatory Redeemable Preferred Stock) (the “Series B Preferred Stock”)

18469P4#4 (Series C Mandatory Redeemable Preferred Stock) (the “Series C Preferred Stock”)

18469#110 (Series D Mandatory Redeemable Preferred Stock) (the “Series D Preferred Stock”).

18469#128 (Series E Mandatory Redeemable Preferred Stock) (the “Series E Preferred Stock”).

18469#136 (Series F Mandatory Redeemable Preferred Stock) (the “Series F Preferred Stock”)

18469#144 (Series G Mandatory Redeemable Preferred Stock) (the “Series G Preferred Stock”)

The Series A Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock, Series E Preferred Stock, Series F Preferred Stock and Series G Preferred Stock together form a single class of the Issuer’s preferred equity securities and are collectively referred to in this Schedule 13G as the “Mandatory Redeemable Preferred Stock”.

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:

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

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

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

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

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

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

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

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

(i) ☐ 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);

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

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

If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

ITEM 4. OWNERSHIP.

(a) Amount beneficially owned: 100

(b) Percent of class: 20.83%

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

(i) Sole power to vote or to direct the vote: 0

(ii) Shared power to vote or to direct the vote: 100

(iii) Sole power to dispose or to direct the disposition of: 0

(iv) Shared power to dispose or to direct the disposition of: 100

ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF CLASS.

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following ☐.

ITEM 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

Certain of AIG’s subsidiaries have the right to receive or the power to direct the receipt of dividends from, and the proceeds from the sale of, the Mandatory Redeemable Preferred Stock. American General Life Insurance Company, Lexington Insurance Company and The United States Life Insurance Company in the City of New York, each an indirect wholly owned subsidiary of AIG, beneficially own 47, 33 and 20 shares, respectively, of the Mandatory Redeemable Preferred Stock.

ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY OR CONTROL PERSON.

See Exhibit 99.1.

ITEM 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.

Not applicable.

ITEM 9. NOTICE OF DISSOLUTION OF GROUP.

Not applicable.

ITEM 10. CERTIFICATION.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: November 30, 2018

AMERICAN INTERNATIONAL GROUP, INC.
By	/s/ Geoffrey N. Cornell
Name:	Geoffrey N. Cornell
Title:	Vice President and Deputy AIG Chief Investment Officer

EX-99.1

Exhibit 99.1

IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY OR CONTROL PERSON.

American International Group, Inc. — Subsidiary Information for the Mandatory Redeemable Preferred Shares:

American General Life Insurance Company:

Insurance Company pursuant to Rule 13d-1(b)(1)(ii)(C)

Category Symbol: IC

Lexington Insurance Company:

Insurance Company pursuant to Rule 13d-1(b)(1)(ii)(C)

Category Symbol: IC

The United States Life Insurance Company in the City of New York:

Insurance Company pursuant to Rule 13d-1(b)(1)(ii)(C)

Category Symbol: IC