(Reuters) - U.S. energy infrastructure company Glenfarne said on Wednesday its unit struck a 20-year deal to sell liquefied natural gas to trading firm Gunvor, moving its planned Brownsville export project in Texas closer to a final investment decision.

The deal covers 0.5 million tonnes per annum of LNG on a free-on-board basis and converts a previous preliminary agreement between the two firms.

Global demand for LNG has surged since Russia's invasion of Ukraine upended gas markets in 2022, driving buyers in Europe and Asia to lock in long-term supply deals with U.S. exporters.

The U.S. had emerged as the world's top LNG supplier in 2023, with Texas and Louisiana at the centre of new capacity growth since.

Texas LNG, a unit of Glenfarne Energy Transition, is developing the Brownsville project, with engineering, procurement and construction to be led by contractor Kiewit.