Italy's Grimaldi Group has expanded its order for ro-ros in China to 12 units.
The company told TradeWinds it had declared options for six more 64,000-gt ships at Nanjing Jinling Shipyard.
They will be delivered in 2021, according to Clarksons.
The move follows an initial order for six vessels there at a cost of $400m in April.
These are due in 2020.
