Indaba Capital Management, which opposes Stagwell’s revised offer for MDC Partners, criticizes it as a “sweetheart transaction.”

ICM managing partner Derek Schrier dismisses the $100M enhanced bid as “insufficient” and “a small and arbitrary number” when compared to MDC’s $1.8B valuation.

In his June 8 letter to Stagwell CEO Mark Penn, Schrier questions the independence of three directors nominated June 7 by Stagwell for board seats since “they all appear to have professional overlap with you.”

He wrote: “Stagwell seems to be trying to stack the board of directors with your allies and former colleagues. As a potential minority shareholder in the newly combined entity, we find this lack of true independence alarming.”

He urges Stagwell to come up with a credible offer, “rather than continuing to issue press releases ad nauseum and trying to spin shareholders.”

ICM “is ready and willing to engage with you to determine what it will take to earn Indaba’s vote,” wrote Schrier.

MDC’s shareholder meeting is scheduled for June 22.

Stagwell's PR units are SKDKnickerbocker and Sloane & Co, while MDC owns Allison+Partners, Veritas, Hunter and KWT Global.