BP will shut its Brisbane refinery in mid-2015 with the loss of more than 350 jobs, as a result of intense competition from large Asian refineries.
The closure will occur about six months after Caltex Australia shuts down its Kurnell refinery in Sydney, with the loss of more than 600 jobs.
In both cases, the closures will hit a large number of contractor and supplier jobs as well, with an estimated 300 contractors to be affected by the Brisbane refinery's closure.
''The best option for strengthening BP's long-term supply position in the east coast retail and commercial fuels markets is to purchase product from other refineries,'' the head of BP Australasia, Andy Holmes, said. ''And while more of our transport fuel demand will be met by imports in future, ample supplies are available to maintain Australia's energy security.''
The switch will ''significantly improve our competitive position'', Mr Holmes said.
In the future, BP will source some of its refined oil products for the Brisbane market from the nearby Caltex refinery at Lytton, with Caltex to invest $30 million on a pipeline to connect the two plants.
BP said it will keep part of the Bulwer Island facility on care and maintenance, which will leave open the option of converting the plant to an import terminal.
At 102,000 barrels a day, the Bulwer refinery is uncompetitive compared with large refineries in Asia. That, together with the strong dollar, has undermined the competitive position of local refiners.
The closure will leave BP operating the 146,000-barrel-a-day Kwinana refinery near Perth as its sole domestic refinery. This unit is able to source crude oil from northern Australia that gives it a more secure position in the local market.
The latest closure means that only four of the eight refineries that were operating in 2003 are left today, all built at least 50 years ago.
They are BP's Kwinana unit, Shell's Geelong refinery, which has just been sold to Vitol of Switzerland, Caltex's Lytton refinery and Exxon-Mobil's Altona refinery.