DryShips shares have skyrocketed in early-morning trading today after chief executive George Economou made an offer to buy the New York-listed diversified owner.

Economou is offering to acquire DryShips through private interest SPII Holdings in a $4 per share conversion offer, according to an SEC filing.

"We believe that private ownership is in the best interests of the company, as it would result with the flexibility to focus on a long-term perspective without being constrained by the public company emphasis on achieving short term results," the subsidiary said in the filing.

"Accordingly, we are confident that this proposal not only offers compelling value to the company's shareholders but is also in the best interests of the company and its other constituencies."

DryShips stock has jumped 24% to $3.93 since yesterday's closing bell.

Calls to DryShips were not immediately returned.

SPII Holdings listed other benefits to the proposed offer, including that it represents a roughly 27% premium to DryShips' closing price of $3.16 yesterday and an approximate 20% premium to the volume-weighted average price over the last 10 trading days.

The transaction would also allow DryShips shareholders to realise "an attractive value in cash" for their investment, which in turn provides them with certainty of value in those shares.

DryShips' board of directors has formed a special committee consisting solely of disinterested directors to consider the proposal.

DryShips, which is 83.4% owned by chairman and chief executive George Economou, earlier this week fully acquired Connecticut-based tanker pool operator Heidmar.

DryShips' diversified fleet consists of 20 dry bulk ships, six tankers and six offshore support vessels.