DryShips, a New York-listed shipowner already facing a heavy debt burden, is likely to retain the liability for a $650m debt accumulated to build an offshore oil-drilling business it now wants to spin off, the company has admitted.

The company is also in breach of the conditions on nearly half its $3bn borrowings and has no guarantee that it will be able to reach agreement with its creditor banks about changing the conditions, it has declared in filings with the US Securities and Exchange Commission (SEC).