New York-listed Seaspan Corporation has bought a 2010-built boxship for a charter to Japanese group ONE.

The shipowner said the 9,600-teu vessel was booked by ONE at a fixed rate for 36 months.

There is an option for an additional four months.

The only ship in the Clarksons SIN database that meets the specifications is the 9,954-teu Navios Unison, acquired from Capital Maritime & Trading last year by Navios Containers, which has been contacted for comment.

Seaspan did not give a price, but VesselsValue assesses the post-panamax unit at $49.06m.

It cost $50.25m in 2018.

Seaspan expects to take delivery of the vessel by the end of April 2020, boosting its fleet to 113 vessels.

Seaspan has a total capacity of more than 900,000 teu with an average age of about seven years.

The average remaining lease period is four years.