UNITED STATES SECURITIES AND
EXCHANGE COMMISSION
Washington, D.C. 20549
Schedule 13G
Under the Securities Exchange Act of 1934
Information to be included in statements filed
pursuant to Rule 13d-1 (b) (c) and (d) and Amendments thereto
filed pursuant to Rule 13d-2 (b).
Sinclair Broadcast Group, Inc.
(Name of Issuer)
Common Stock Class A
(Title of Class of Securities)
829226109
(CUSIP Number)
May 31, 2007
(Date of Event which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant
to which this Schedule is filed:
[x] 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 the 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).
SCHEDULE 13G
Issuer: Sinclair Broadcast Group, Inc. CUSIP No.: 829226109
1 NAMES OF REPORTING PERSONS I.R.S.
IDENTIFICATION NOS. OF ABOVE PERSONS
MacKay Shields LLC
IRS# 13-4080466;
2 CHECK THE APPROPRIATE BOX IF A MEMBER
OF A GROUP
(a)
(b)
3 SEC USE ONLY
4 CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware (United States)
NUMBER OF SHARES 5 SOLE VOTING POWER 3,164,767
BENEFICIALLY 6 SHARED VOTING POWER 0
OWNED BY
EACH 7 SOLE DISPOSITIVE POWER 3,164,767
REPORTING
PERSON 8 SHARED DISPOSITIVE POWER 0
WITH
9 AGGREGATE AMOUNT BENEFICIALLY OWNED
BY EACH REPORTING PERSON
Total: 3,164,767
10 CHECK IF THE AGGREGATE AMOUNT IN
ROW (11) EXCLUDES CERTAIN SHARES
Not Applicable
11 PERCENT OF CLASS REPRESENTED BY AMOUNT
IN ROW 11
5.83%
12 TYPE OF REPORTING PERSON
IA
SCHEDULE 13G
Issuer: Sinclair Broadcast Group, Inc. CUSIP No.: 829226109
ITEM 1
(a) Name of Issuer:
Sinclair Broadcast Group, Inc.
(b) Address of Issuer's Principal Executive Offices:
10706 Beaver Dam Road
Hunt Valley, MD 21030
ITEM 2(a) Name of Person Filing:
MacKay Shields LLC
(b) Address of Principal Business Office:
9 West 57th Street
New York, NY 10019
(c) Citizenship:
United States
(d) Title of Class of Securities:
Class A Common Stock, $0.01 par value
(e) CUSIP Number: 829226109
ITEM 3
If this statement is filed pursuant to Sections 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 if 1940
(15 U.S.C. 80a-8);
(e) [X] An investment adviser in accordance with Section
240.13d-1(b)(1)(ii)(E);
(f) [ ] An employee benefit plan or endowment fund in
accordance with Section 240.13d-1(b)(1)(ii)(F);
(g) [ ] A parent holding company or control person in
accordance with Section 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 insurance company under
Section 3 (c)(14) of the Investment Company
Act of 1940 (15 U.S.C. 80a-3);
(j) [ ] Group, in accordance with section
240.13d-1 (b)(1)(ii)(J).
SCHEDULE 13G
Issuer: Sinclair Broadcast Group, Inc. CUSIP No.: 829226109
ITEM 4. Ownership.
MacKay Shields LLC, an investment adviser registered under
Section 203 of the Investment Advisers Act of 1940, is deemed to be
the beneficial owner of 3,164,767 shares or 5.83% of the Common
Stock believed to be outstanding as a result of acting as investment
adviser to various clients. The amount deemed beneficially owned
includes 110,290 shares of common stock and 3,054,477 shares of common
stock issuable upon the conversion of 62,403 of the 3% convertible
bonds due May 15, 2027 of the Issuer with a conversion rate of 48.9476.
The percent of class is calculated based on 54,316,478 shares of common
stock outstanding, which is calculated by adding 51,262,001 (the number
of shares of common stock outstanding of the Company as of May 31, 2007)
and 3,054,477 (the number of shares of common stock deemed held as a
result of the beneficial ownership of the convertible bond).
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
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 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 such securities and were
not acquired and are not held in connection with or as a participant
in any transaction having that purpose of effect.
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: June 5, 2007
Signature: /s/ Rene A. Bustamante
Name/Title: Rene A. Bustamante
Chief Compliance Officer