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<TYPE>EX-99.77O RULE 10F-3
<SEQUENCE>4
<FILENAME>77o30.txt
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                                                            [LOGO OF BLACKROCK]

Rule 10f-3 Transaction Form

Acquisition of Securities During Affiliated Underwritings

PARTICIPATING FUNDS

.   U.S. Registered Funds (Name of Fund, Aladdin Ticker):
    BlackRock Strategic Municipal Opportunities Fund of BlackRock Series Trust
    (BR-SMO-IG)
    BlackRock Allocation Target Shares : Series E Portfolio (BATSE)
    BlackRock High Yield Municipal Fund (BR-HYMUNI)
    BlackRock Long-Term Municipal Advantage Trust (BTA)
    BlackRock MuniAssets Fund, Inc. (MUA)

THE OFFERING

KEY CHARACTERISTICS (COMPLETE ALL FIELDS)

Date of                    05-10-2017
Offering Commencement:

Security Type:             BND/MUNI

Issuer                     COUNTY OF CUYAHOGA, OHIO HOSPITAL REVENUE BONDS,
                           SERIES 2017

Selling Underwriter        Merrill Lynch, Pierce, Fenner & Smith Incorporated

Affiliated Underwriter(s)  [X] PNC Capital Markets LLC
                           [_] Other:

List of Underwriter(s)     Merrill Lynch, Pierce, Fenner & Smith Incorporated,
                           J.P. Morgan Securities LLC, Fifth Third Securities,
                           Inc., KeyBanc Capital Markets Inc, PNC Capital
                           Markets LLC

TRANSACTION DETAILS

Date of Purchase           05-10-2017

Purchase Price/Share       $ 103.975 Total Commission, Spread or Profit  0.526%
(PER SHARE / % OF PAR)     $ 103.021
                           $ 104.404
                           $ 100.374
                           $ 105.379
                           $ 104.588
                           $  99.478

 1.  Aggregate Principal Amount Purchased (a+b)                     $76,450,000

     a.  US Registered Funds
         (Appendix attached with individual Fund/Client purchase)   $76,450,000

     b.  Other BlackRock Clients                                            N/A

                                                                    Page 1 of 2

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Rule 10f-3 Report - Definitions                            [LOGO OF BLACKROCK]



2.  Aggregate Principal Amount of Offering                         $945,660,000

FUND RATIO
[Divide Sum of #1 by #2]
Must be less than 0.25                                                  0.08084

<PAGE>

Rule 10f-3 Report - Definitions                            [LOGO OF BLACKROCK]


LEGAL REQUIREMENTS

OFFERING TYPE (CHECK ONE)

The securities fall into one of the following transaction types (see
Definitions):

[_] U.S. Registered Public Offering... [Issuer must have 3 years of continuous
                                       operations]
[_] Eligible Rule 144A Offering....... [Issuer must have 3 years of continuous
                                       operations]
[X] Eligible Municipal Securities
[_] Eligible Foreign Offering......... [Issuer must have 3 years of continuous
                                       operations]
[_] Government Securities Offering.... [Issuer must have 3 years of continuous
                                       operations]

TIMING AND PRICE (CHECK ONE OR BOTH)

[X] The securities were purchased before the end of the first day on which any
    sales were made, at a price that was not more than the price paid by each
    other purchaser of securities in that offering or in any concurrent
    offering of the securities; and
[_] If the securities are offered for subscription upon exercise of rights, the
    securities were purchased on or before the fourth day before the day on
    which the rights offering terminated.

FIRM COMMITMENT OFFERING (CHECK ONE)

[X] YES  The securities were offered pursuant to an underwriting or similar
[_] NO   agreement under which the underwriters were committed to purchase all
         of the securities being offered, except those purchased by others
         pursuant to a rights offering, if the underwriters purchased any of
         the securities.

NO BENEFIT TO AFFILIATED UNDERWRITER (CHECK ONE)

[X] YES  No affiliated underwriter was a direct or indirect participant in, or
[_] NO   benefited directly or indirectly from, the transaction.

Completed by:             Dipankar Banerjee                 Date:   05-22-2017
                          --------------------------------         ------------
                          Global Syndicate Team Member

Approved by:              Steven DeLaura                    Date:   05-22-2017
                          --------------------------------         ------------
                          Global Syndicate Team Member

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Rule 10f-3 Report - Definitions                            [LOGO OF BLACKROCK]

DEFINITIONS

TERM                       DEFINITION
Fund Ratio                 Number appearing at the bottom of page 1 of 2 of
                           the Rule 10f-3 Report form. It is the sum of the
                           Funds' participation in the offering by the Funds
                           and other accounts managed by BlackRock divided by
                           the total amount of the offering.

Eligible Foreign Offering  The securities are sold in a public offering
                           conducted under the laws of a country other than
                           the United States and

                           (a) the offering is subject to regulation in such
                               country by a "foreign financial regulatory
                               authority," as defined in Section 2(a)(50) of
                               the Investment Company Act of 1940;

                           (b) the securities were offered at a fixed price to
                               all purchasers in the offering (except for any
                               rights to purchase securities that are required
                               by law to be granted to existing security
                               holders of the issuer);

                           (c) financial statements, prepared and audited as
                               required or permitted by the appropriate
                               foreign financial regulatory authority in such
                               country, for the two years prior to the
                               offering, were made available to the public and
                               prospective purchasers in connection with the
                               offering; and

                           (d) if the issuer is a "domestic issuer," i.e.,
                               other than a foreign government, a national of
                               any foreign country, or a corporation or other
                               organization incorporated or organized under
                               the laws of any foreign country, it (1) has a
                               class of securities registered pursuant to
                               section 12(b) or 12(g) of the Securities
                               Exchange Act of 1934 or is required to file
                               reports pursuant to section 15(d) of that act,
                               and (2) has filed all the material required to
                               be filed pursuant to section 13(a) or 15(d) of
                               that act for a period of at least 12 months
                               immediately preceding the sale of securities
                               (or for such shorter period that the issuer was
                               required to file such material)

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Rule 10f-3 Report - Definitions                            [LOGO OF BLACKROCK]


TERM                             DEFINITION
Eligible Municipal Securities    The securities:

                                 (a) are direct obligations of, or obligations
                                     guaranteed as to principal or interest
                                     by, a State or any political subdivision
                                     thereof, or any agency or instrumentality
                                     of a State or any political subdivision
                                     thereof, or any municipal corporate
                                     instrumentality of one or more States, or
                                     any security which is an industrial
                                     development bond (as defined in section
                                     103(c)(2) of Title 26) the interest on
                                     which is excludable from gross income
                                     under certain provisions of the Internal
                                     Revenue Code;

                                 (b) are sufficiently liquid that they can be
                                     sold at or near their carrying value
                                     within a reasonably short period of time;
                                     and

                                 (c) either

                                     (1) are subject to no greater than
                                         moderate credit risk; or

                                     (2) if the issuer of the municipal
                                         securities, or the entity supplying
                                         the revenues or other payments from
                                         which the issue is to be paid, has
                                         been in continuous operation for less
                                         than three years, including the
                                         operation of any predecessors, the
                                         securities are subject to a minimal
                                         or low amount of credit risk.

                                 Also, purchases of municipal securities may
                                 not be designated as group sales or otherwise
                                 allocated to the account of any prohibited
                                 seller (i.e., an affiliated underwriter).

Eligible Rule 144A Offering      The securities are sold in an offering where

                                 (a) the securities are offered or sold in
                                     transactions exempt from registration
                                     under Section 4(2) of the Securities Act
                                     of 1933, Rule 144A thereunder, or Rules
                                     501-508 thereunder;

                                 (b) the securities were sold to persons that
                                     the seller and any person acting on
                                     behalf of the seller reasonably believe
                                     to include qualified institutional
                                     buyers, as defined in Rule 144A ("QIBs");
                                     and

                                 (c) the seller and any person acting on
                                     behalf of the seller reasonably believe
                                     that the securities are eligible for
                                     resale to other QIBs pursuant to Rule
                                     144A.

Government Securities Offering   The security is issued or guaranteed as to
                                 principal or interest by the United States,
                                 or by a person controlled or supervised by
                                 and acting as an instrumentality of the
                                 Government of the United States pursuant to
                                 authority granted by the Congress of the
                                 United States; or any certificate of deposit
                                 for any of the foregoing.

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Rule 10f-3 Report - Definitions                            [LOGO OF BLACKROCK]


TERM                              DEFINITION
U.S. Registered Public Offering.  The securities offered are registered under
                                  the Securities Act of 1933 that are being
                                  offered to the public.
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