Danaos Corp expressed “serious concern” on Tuesday over Eagle Bulk Shipping’s “unilateral” decision to adopt a poison pill that blocks the Greek firm from increasing its stake in the Gary Vogel-led company.

Eagle Bulk’s decision “to adopt the poison pill without seeking the prior approval of shareholders raises the question of whether the board is truly acting in the best interests of stockholders”, Piraeus-based Danaos — Eagle Bulk’s largest shareholder — said in an outspoken public letter to the company’s management.