MDC Partners Inc. (MDCA) and Stagwell Marketing Group LLC Schedule Conference Call to Discuss Financial Results for the Three Months Ended June 30, 2021 PR Newswire NEW YORK, July 28, 2021 NEW YORK , July 28, 2021 /PRNewswire/ -- (NASDAQ: MDCA) – MDC Partners Inc. ("MDC Partners" or the "Company") and Stagwell Marketing Group LLC ("Stagwell") announced today that both companies will report separate financial results for the three months ending June 30, 2021 on Wednesday, August 4, 2021 ,...