Chinese owner Zhejiang Yonghang Shipping has moved to expand its dry bulk fleet with an order for up to six ultramax bulk carriers at Yangfan Group.

The two sides have signed a contract covering four firm 64，500 dwt vessels plus options for two additional ships， according to information released by the shipbuilder.

The vessels have been designed by the Shanghai Merchant Ship Design and Research Institute (SDARI)， will be classed by China Classification Society， fly the Chinese flag and comply with the latest environmental requirements.

Financial terms and delivery dates have not been disclosed， but brokers estimate ultramax newbuild tonnage at Chinese yards at around $34m.

The deal marks a significant fleet investment for Zhejiang Yonghang， which currently operates around 10 smaller bulk carriers and general cargo vessels.

For Yangfan Group， the order represents the second major newbuilding contract announced in recent weeks.

In late May， the shipbuilder secured an order from Baozhou Shipping for up to four 2，700 teu containerships. The programme comprises two firm vessels and two options and will be built at Zhejiang Tenglong Shipbuilding and Zhejiang East Coast Shipbuilding， both part of the Yangfan Group.