DryShips Inc. (DRYS) unveiled a bigger-sized sale of its stake in Ocean Rig UDW Inc. (ORIG) as the dry bulk shipper pares its stake in the offshore drilling services provider by about 10%.

Ocean Rig's shares began trading on Nasdaq in October after a partial spinoff of the offshore drilling services provider by DryShips. Ocean Rig shares are up by roughly a third year to date.

The dry-bulk shipper said 10 million shares priced at $16.25 each, a penny discount from Wednesday's close. Companies affiliated with Ocean Rig's Chairman and Chief Executive George Economou have agreed to purchase 1.9 million shares from DryShips at the offer price.

On Monday, DryShips offered to sell 9 million of its Ocean Rig shares while companies affiliated Economou were expected to purchase a minimum of 900,000 shares. Before the stock sale, DryShips owned about 97.3 million Ocean Rig shares.

In March, Ocean Rig unveiled a planned share sale by DryShips--its largest shareholder--of up to $100 million, in a filing with the U.S. Securities and Exchange Commission. The company recently had about 263.4 million shares outstanding, according to FactSet Research.

Ocean Rig offers offshore drilling services for oil and gas exploration, and development in
Norway and other countries.

DryShips shares were up slightly at $3.21 in early trading. Shares of Ocean Rig were up 4.4% at $16.98.