New York-listed Seaspan has netted five-year charters for four 10,000-teu vessels under construction at New Yangzi Shipbuilding and Jiangsu Yangzi Xinfu Shipbuilding.

The charters, which include options for two more years, are worth $130m, the boxship owner says.

Seaspan, which has taken its contract backlog to $6.1bn with the deal, explains two of the vessels were previously controlled by its Greater China Intermodal Investments venture but will now move to the public company.