A STRONG Australian dollar has pushed Sydney and Melbourne up on the list of the world's most expensive cities for expatriate workers, according to a global cost of living survey.

The research, which measured the cost of living in 143 cities, revealed prices are rising in Australia's major cities - particularly in Melbourne, which catapulted 28 places to become the 36th most expensive city.

Sydney remains the nation's most costly city, jumping six places to be ranked as the world's 15th most expensive city.

The Mercer Consulting Group survey, taken in March, is based on the needs of expatriates and measures the comparative cost of more than 200 items including transport, food and housing. The rankings are relative to New York, which is the reference point and has an index rating of 100.

"Without a doubt, Australian cities are becoming more expensive," said Mercer executive Rob Knox.