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 *
ROSENBERG GRAHAM LAWRENCE
   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)
03/20/2006
(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)               67,304 D  
Class A Subordinate Voting Shares 03/20/2006   S   14,800 D $ 9.59 (2) 52,504 D  
Class A Subordinate Voting Shares               4,000 I Owned by spouse
Class A Subordinate Voting Shares 03/20/2006   P   14,800 A $ 9.59 (2) 18,800 I Owned by spouse

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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 Appreciation Rights (3) $ 9.71 (2)             07/30/2004 07/30/2007 Class A Subordinate Voting Shares 13,333   13,333 D  
Stock Options (4) $ 5.4 (2)             10/09/2002 10/09/2007 Class A Subordinate Voting Shares 13,000   13,000 D  
Stock Options (5) $ 8.4 (2)             07/31/2003 04/09/2012 Class A Subordinate Voting Shares 47,625   47,625 D  

Reporting Owners

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

Signatures

 Graham L. Rosenberg   03/22/2006
**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) of the Issuer (previously granted on February 28, 2006) which may vest in each of 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 Appreciation Rights (previously granted on July 30, 2003) vest 1/3 on each anniversary of the grant date, expire four years from the grant date, and are settled in cash or or stock, at the option of the Issuer.
(4) 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.
(5) Stock Options (previously granted July 31, 2003) are deemed to have fully vested on the grant date.

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