May 3 (Reuters) - U.S. pipeline operator Energy Transfer LP said on Tuesday it will supply 0.4 million tonnes of liquefied natural gas (LNG) per year to South Korea's SK Gas Trading LLC for 18 years.

Long-term LNG contracts are ramping up as sanctions on Russian fuel squeeze an already tightly supplied market and increase global demand for U.S. LNG.

Energy Transfer said first deliveries are expected to begin in 2026 from its Lake Charles export facility in Louisiana.

This is Energy Transfer's fourth supply deal announced in the last four weeks, bringing the total LNG contracted from its Lake Charles project to 5.1 million tonnes per year. (Reporting by Ruhi Soni in Bengaluru; Editing by Krishna Chandra Eluri)