Cosco Shipping Lines has said it is not the operator of the panamax containership which lost an undisclosed number of containers in a Pacific storm.

The 4,526-teu Cosco Nagoya (built 2008) was understood to have lost containers en route to Long Beach, a day after departing from the Busan New Port in South Korea, on 23 November.

Around 59 containers are estimated to have been damaged or lost. Container claims specialist WK Webster said, shortly after the accident, "early indications are this may have been quite a serious incident".

Reports have linked the incident to Cosco Shipping Lines. But the Chinese containership operator has now released a statement clarifying that, despite the ship's name, it has not been involved with the vessel for more than a year.

"Cosco Shipping Lines notices recent media reports regarding the massive container collapse happening to Cosco Nagoya. The company hereby affirms that Cosco Nagoya had come off charter and has not been operated by Cosco Shipping Lines since April 2020," it said in a statement.

The vessel is owned by Japan's Doun Kisen. According to market reports, it was chartered out to Singapore and Dubai-based operator Sea Lead Shipping in December 2020 for a period of one year and nine months at a rate of $23,750 per day. The vessel is listed on the Sea Lead website.

The vessel headed to the port of Gwangyang in South Korea after the container losses. AIS now indicates the vessel has resumed its voyage to Long Beach from 7 December.

Sea Lead has been contacted for comment on the status of the vessel.

The incident had raised alarm because there was a series of major container stack collapses in the Pacific during last winter. There is some concern that the latest incident could indicate another series of losses is likely during the current winter period, as containerships continue to operate at full capacity.

The container losses last winter included the 14,026-teu ONE Apus (built 2019), the 13,092-teu Maersk Eindhoven (built 2010) and the 13,092-teu Maersk Essen (built 2010).

In October 2021 4,253-teu ZIM Kingston (built 2008) lost an estimated 100 containers in a storm and fire off the Port of Vancouver, Canada.