The strong Australian dollar caused Sydney and five other Aussie cities to have major boosts in their ranking of the world's most expensive cities for expatriates. Based on the 2012 Mercer Worldwide Cost of Living Survey released on Wednesday, Sydney was the 11th city with the highest cost of living.

Sydney jumped by three sports from 14th place in 2011. Other Australian cities on the list of the 19 most expensive global cities are Melbourne, which went up to 15th from 21st spot, and Perth, which leapfrogged 11 spots to 19th place due to the mining boom that caused prices to zoom across the board.

Outside Australia, the top four most expensive cities are Tokyo in Japan, Luanda in Angola, Osaka in Japan and Moscow in Russia.

In moving to 11th place, Sydney skipped Sao Paolo and Rio de Janeiro in Brazil. Meanwhile, Melbourne overtook Beijing and Shanghai.

Nathalie Constantin-Metral of Mercer, who supervised the compilation of the list, explained the upward movement of Australian and New Zealand cities to the strength of their currencies.

One impact of the high cost of living in these cities was that it boosted demand for rental properties which was worsened with limited availability.

Three other Australian cities are in the top 50 - Canberra at 23rd place from 34th, Brisbane at 24th spot from 31stand Adelaide which zoomed 19 places to 27th from 46th place. Among major Australian capital cities, only Darwin failed to make it on the list.

Another publication, The Economist, said Australia has the most overvalued property markets.