It has added four 38,500-dwt bulkers for delivery in the first half of 2017 from Zhejiang Yangfan, it said.
The series was kicked off with four vessels last year and four more were contracted in January, pegged by brokers at between $22m and $23m each.
Deltamarin has designed the ships to carry grain, fertilisers and coal.
The terms of the contract are confidential, PZM added.
