Defending Samsung Heavy Industries and the other entity in patent infringement lawsuit concerning FLNG Vessel

Lee & Ko’s IP & Technology Practice Group has been successfully representing Samsung Heavy Industries and another entity in a patent infringement lawsuit filed by Canada’s Steelhead LNG against Samsung Heavy Industries and the entity before the Seoul Central District Court in connection with the Canadian FLNG project being carried out by Samsung Heavy Industries and Canada’s Cedar LNG, thereby contributing to the smooth execution of the project.

Cedar FLNG is a nearshore FLNG model that receives natural gas supplied from onshore facilities and is capable of liquefying, storing, and offloading the gas. It is an ultra-large offshore plant, with a hull area 2.5 times the size of a soccer field and a launch weight of approximately 50,000 tons. With respect to the FLNG vessel being constructed by Samsung Heavy Industries, In December 2024, Steelhead filed a patent infringement lawsuit alleging infringement of two patents and seeking, among other relief, an injunction halting construction.

Lee & Ko’s IP & Technology Practice Group defended against the infringement lawsuit by asserting non-infringement, while at the same time filing invalidation actions against Steelhead’s patents. Although Steelhead responded by amending its patent claims, Lee & Ko’s effective invalidity arguments were accepted, and the Intellectual Property Trial and Appeal Board (“IPTAB”) held both patents to be invalid in May 2026. The IPTAB found not only that both patents lacked an inventive step compared to the prior art, but also that the amendments made during the prosecution process constituted the addition of new matter, and therefore held that grounds for invalidity existed independent of the lack of inventive step.

As both patents were successfully held invalid by the IPTAB, the likelihood that Steelhead’s patent infringement lawsuit based on those patents will be dismissed has increased significantly. This is highly significant in that Samsung Heavy Industries is now able to carry out this massive project, with a total project cost of USD 4 billion, in a stable manner and without litigation risk.