Hong Kong-listed China Cosco is paying $175.62m for the four supramax and two panamax newbuildings at Chinese shipyards.
Cosco explained in a statement the latest contracts fit a plan to both upgrade and improve the competitiveness of its fleet.
The 64,000-dwt quartet has been booked by Cosco company Prosperity Investment at CSSC Huangpu Wenchong in a $113.12m pact.
A further two 78,000-dwt bulkers have been contracted at Jiangnan Shipyard at a cost of $62.5m.
Cosco