The global petroleum company Caltex is closing its refinery in the Sydney suburb of Kurnell, causing the loss of more than 300 jobs.
The company says the operation is no longer financially viable in the face of competition from big Asian refineries.
Caltex says it will close Kurnell by the middle of 2014, after 57 years of operation, and instead use the facility to import fuel refined overseas.
The ABC reports that a review of the plant's operations had been announced in May as part of a major restructuring of the company's supply chain.
Staff numbers are expected to be reduced from 430 to about 100.
The company says the carbon tax recently introduced by the federal government had no impact on the decision.
Sydney will now be without a refinery for the first time in nearly 60 years. Caltex, Shell and ExxonMobil between them run six others in Australia - two in Victoria, two in Queensland and one each in South Australia and Western Australia.
The government says the closure won't jeopardise the country's energy security.
