It has declared options for the ships, which are set for delivery in September and November 2016, respectively.
The Lubeck-based company is believed to be paying $52m per ship.
Oldendorff now has 24 bulkers of this size on order at yards in China and South Korea, more newcastlemax newbuildings than any other owner. The ships are today probably worth $60m each.
The company, whose extensive newbuilding programme includes other ship sizes, is also involving itself in asset play.
