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.
The vessels will be able to transport over 7,800 lane metres of rolling units, equivalent to approximately 500 trailers.
In May, it confirmed it was in talks with Xiamen Shipbuilding for an order for six more ro-ro vessels.
The group is aiming to add 20 such ships in total, with another two coming from the second-hand market.
It wants to buy two modern ropaxes from European companies.
The group has 110 operational vessels.
Seven car carriers are also on order at Zhejiang Yangfan.
