Sydney has again been named Australia's most expensive city.

Sydney has been ranked the seventh most expensive city in the world in a cost of living survey of 130 cities by the Economist Intelligence Unit, compared with sixth last time.

Sydney is one of the world's most expensive cities. Credit:Michele Mossop

"The cost of living in Sydney is now almost 50 per cent higher than that of global business centre New York – while a decade ago Sydney was more than 25 per cent cheaper than New York," Worldwide Cost of Living report editor Jon Copestake said from London.

"The cost of a loaf of bread in Sydney has almost doubled in the past decade in US dollar terms, while petrol prices have risen threefold and rice prices have almost quadrupled," Mr Copestake said.