July 10 (Reuters) - Chevron Australia CVX.N said on Friday it has signed a long-term agreement with energy retailer Alinta Energy to supply natural gas from its Western Australian portfolio.

Chevron said starting July 2027 it will supply 46 petajoules of gas to its long-standing partner Alinta Energy over a five- year period from across its equity interests in the Chevron-operated Gorgon and Wheatstone facilities, and the North West Shelf Project.

"Following almost a decade in operation, Gorgon and Wheatstone have become pillars of energy security for the state and together provide approximately 40 percent of WA’s domestic gas supply," Chevron Australia President Balaji Krishnamurthy said in a press release.

Singapore's Sembcorp Industries SCIL.SI acquired Australian gas and electricity provider Alinta Energy for an enterprise value of A$6.5 billion ($4.32 billion) last year.