OSLO (Reuters) – Greek dry-bulk carrier DryShips Inc and its chief executive have taken a controlling stake in Norway-based oil rig group Ocean Rig and will bid for the rest of the stock, the companies said yesterday. Nasdaq-listed DryShips said it bought about 33.25 million Ocean Rig shares at 45 Norwegian crowns per share on Monday – a deal worth about $300 million – adding to earlier holdings to raise its stake to 49.9 percent, DryShips said in a statement. Separately, George Economou, DryShips chairman and chief executive, bought a stake of about 4.4 percent, DryShips said. The offer values all of Ocean Rig at about $1.53 billion. Oslo-listed Ocean Rig shares traded up 5.4 percent at 45.20 crowns at 0949 GMT, just above the price paid for the stake. «As a consequence of yesterday’s acquisition DryShips Inc will commence a mandatory tender offer for the remaining outstanding shares in Ocean Rig ASA within the four weeks deadline set by Oslo Stock Exchange rules,» the company said. «DryShips will use a combination of cash on hand and debt financing which is already in place to acquire the remaining outstanding shares of Ocean Rig,» it added. DryShips said that acquiring Ocean Rig would help it to diversify its assets and sources of cash flow, and said that a recent giant oil discovery off Brazil increased the attractiveness of getting into the rig business. «I am very excited by the opportunity of increasing our ownership significantly and the prospect of acquiring Ocean Rig,» Economou said in the statement. DryShips said its belief in dry-bulk shipping remained unchanged but that it expected its investment in the ultra-deepwater rig business to boost shareholder values «as the extremely bullish fundamentals of the sector unfold.» «Going forward we plan to expand our asset portfolio with further acquisitions and explore other strategic alternatives including the possibility of spinning off this business unit to our shareholders,» it said. Ocean Rig, which owns and operates two ultra-deepwater rigs, urged its shareholders to take no action until the mandatory offer is clarified. «We must see what is in the mandatory offer before we can make a statement,» Ocean Rig chairman Geir Aune told Reuters. Aune declined to say if he thought any other players could make a competing offer for the company.