Canadian tonnage provider Seaspan has offloaded a couple of older container ships while adding two more modern vessels.

The shipowner said in a US filing it had sold a panamax unit to Japanese shareholder Ocean Network Express (ONE) in the second quarter, for net proceeds of $17.25m.

Seaspan is continuing to manage the vessel, which brokers said was the 4,253-teu Seaspan New York (built 2005).

The group has also bought two 8,100-teu vessels from ONE for a total price of $54.4m.

These are the ONE Continuity and ONE Cosmos (both built 2008).

Seaspan has also completed the sale of a 4,250-teu container unit to an Asian player for gross proceeds of $26m and a gain of $5m.

Brokers said the ship was the Felixstowe (built 2002), with Japanese interests reported to have taken the vessel.

Seaspan's parent Atlas Corp, previously listed in New York, was taken private by its major shareholders in March.

The group said Seaspan’s net earnings were $120.8m for the second quarter, against $160.6m in the same period of 2022.

Revenue grew to $403.4m from $378.8m, but interest costs hit $82m, versus $46.5m last year.

During the six months ended 30 June, the company took delivery of seven newbuildings, ranging in size from 15,000 teu to 15,500 teu. These cost $896m.

The group still has 51 ships being built after a huge order spree in the last couple of years.

The March delisting was the result of a $10.9bn take-private merger plan.

The deal was unveiled in August last year by Poseidon’s shareholders, including affiliates of Fairfax Financial Holdings, the Washington family and Atlas chairman David Sokol, which together already controlled 68% of the company.