Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Swartzman Gavin
  2. Issuer Name and Ticker or Trading Symbol
MDC PARTNERS INC [MDCA]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Managing Director
(Last)
(First)
(Middle)
C/O MDC PARTNERS INC., 45 HAZELTON AVENUE
3. Date of Earliest Transaction (Month/Day/Year)
09/13/2006
(Street)

TORONTO, A6 M5R 2E3
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Class A Subordinate Voting Shares (1)               46,898 D  
Class A Subordinate Voting Shares 09/13/2006   S   2,000 D $ 8.46 (2) 44,898 D  
Class A Subordinate Voting Shares 09/14/2006   S   2,000 D $ 8.52 (2) 42,898 D  

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Options (3) $ 5.4 (2)             10/09/2002 10/09/2007 Class A Subordinate Voting Shares 21,000   21,000 D  
Stock Appreciation Rights (4) $ 13.61 (2)             08/24/2005 08/24/2008 Class A Subordinate Voting Shares 30,000   30,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Swartzman Gavin
C/O MDC PARTNERS INC.
45 HAZELTON AVENUE
TORONTO, A6 M5R 2E3
      Managing Director  

Signatures

 Gavin Swartzman   09/15/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Includes 35,000 Financial Performance-Based Restricted Stock Units (Class A Shares) which were previously granted on February 28, 2006, a portion of which may vest in 2007, 2008 and/or 2009 if the Issuer achieves specified financial performance targets in 2006 - 2008, and is dependent on continued employment. Such financial targets are set forth in a "Financial Performance-Based Restricted Stock Unit Agreement", a form of which was filed by the Issuer as an exhibit to a Form 8-K filed with the SEC on March 2, 2006.
(2) Canadian dollars.
(3) Stock Options, previously granted on October 9, 2002, vest 1/5 on grant and 1/5 on each anniversary of the grant date, expiring five years from the grant date.
(4) Stock Appreciation Rights, previously granted on August 24, 2004, vest 1/3 on the first anniversary of the grant date, expire four years from the grant date, and may be settled in cash or in stock at the option of the Issuer.

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