Danaos Corp chief executive John Coustas and his family have dropped another $25m into the boxship owner, bringing their stake in the company to well over a third.

Danaos Investment Limited as trustee of the 883 Trust purchased 305,118 more common units of Athens-based Danaos, according to a regulatory filing.

The shares fell 1.89% to $81.57 within 45 minutes of Friday's open trading on the Nasdaq stock exchange in New York, thus taking the value of the family's latest investment to $24.9m.