UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO

§ 240.13d-2(a)

(Amendment No. 1)¹

MDC Partners Inc.

(Name of Issuer)

Class A Subordinate Voting Shares, no par value

(Title of Class of Securities)

552697104

(CUSIP Number)

JOAN JIANG
Chief Compiance Officer

Indaba Capital Management, L.P.

One Letterman Drive, Building D, Suite DM700

San Francisco, California 94129

(415) 680-1180

STEVE WOLOSKY, ESQ.
OLSHAN FROME WOLOSKY LLP

1325 Avenue of The Americas

New York, New York 10019

(212) 451-2300

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

June 8, 2021

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box ☒.

Note:  Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits.  See § 240.13d-7 for other parties to whom copies are to be sent.

1              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 disclosures 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 (“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).

The following constitutes Amendment No. 1 to the Schedule 13D filed by the undersigned (“Amendment No. 1”). This Amendment No. 1 amends the Schedule 13D as specifically set forth herein.

Item 4 of the Schedule 13D is hereby amended by adding the following:

On June 8, 2021, the Investment Manager issued an open letter to the Chairman and Chief Executive Officer of the Issuer, Mark Penn (the “June 8 Letter”), expressing its continued concerns with the Issuer’s proposed combination with Stagwell Media LP (“Stagwell”) and dissatisfaction with Stagwell’s revised proposal and had issued a presentation outlining why it opposes the merger on its current terms (the “June 8 Presentation”). In both the June 8 Letter and the June 8 Presentation, the Investment Manager reiterated its intention to vote against the transaction under its current terms. The foregoing descriptions of the June 8 Letter and the June 8 Presentation do not purport to be complete and are qualified in their entirety by reference to the full text of such documents, which are attached hereto as Exhibits 99.1 and 99.2, respectively, and are incorporated herein by reference.

SIGNATURES

After reasonable inquiry and to the best of his knowledge and belief, the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated: June 9, 2021