A rail ferry unit of Seacor Holdings has ordered a new ro-ro at China's Huangpu Wenchong yard.
The 2,000-lane-metre ship is due in 2020.
No price was revealed for the contract with New Orleans-based CG Railway (CGR).
US shipowner Seacor and Genesee & Wyoming Inc formed a 50/50 joint venture to buy CGR in September.
CGR had earlier been acquired by Seacor through its takeover of International Shipholding Corporation.
It has two ro-ro rail ferries, each with the capacity to transport approximately 115 railcars per voyage.
CGR operates a freight railroad providing a four-day service between the ports of Mobile, Alabama, and Coatzacoalcos, Veracruz.
The rail ferry offers a faster and more cost-effective alternative to the traditional land route between the southeast US and southeast Mexico, it said at the time of the JV buyout.
The company said it was planning to immediately invest in the existing rail ferry vessels to enhance service reliability.
Brokers also said the Chinese shipyard has booked a 10,000-gt trailing hopper suction dredger for delivery in 2020 to domestic operator Huanghua Harbor Engineering.
