Trouble brews in the MDC Partners and Stagwell Group merger, as shareholders voice their discontent.

In a significant development, Indaba Capital Management, the largest shareholder of advertising and marketing company MDC, has lodged an official protest against the terms of the proposed merger with Stagwell.

The protest, penned by Derek Schrier, managing partner of Indaba Capital Management, was addressed to the Special Committee formed to manage negotiations around the merger. The letter does not disclose any new information about Indaba Capital Management's ownership stake in MDC or its relationship with Stagwell.

Indaba Capital Management owns 12% of the shares of MDC, making it the company's biggest shareholder. The concerns expressed in the letter suggest that the terms of the MDC-Stagwell merger may be unfavorable to MDC shareholders. However, the letter does not specify what specific terms of the merger it finds unfavorable.

For months, Indaba Capital Management has been explaining its concerns about the merger to MDC and Stagwell chief Mark Penn and the Special Committee. The letter expresses concerns that the merger does not provide "fair consideration" to MDC shareholders.

Despite the protest, the merger deal between MDC and Stagwell remains uncertain. The letter does not propose any alternative terms for the merger nor does it indicate whether Indaba Capital Management intends to withdraw its support for the deal.

The president of Indaba Capital Management who officially opposed the merger agreement between MDC and Stagwell is not identified in the provided search results.

As the Special Committee continues to negotiate the terms of the merger, the protest from Indaba Capital Management raises questions about whether the deal favors Stagwell over MDC shareholders. The outcome of these negotiations will be closely watched by the advertising industry and MDC shareholders alike.