Oil-rich Angolan capital tops cost of living list

Angola's capital Luanda topped this year's Mercer Worldwide Cost of Living Survey as the world's most expensive city for expatriates, with Tokyo in second spot and Ndjamena, Chad, in third.

Karachi in Pakistan was the least costly place for expats in a survey by the consulting firm that covers 214 cities across five continents and measures the comparative costs of more than 200 items in each location.

For the first time, three African cities -- Luanda, Ndjamena and Libreville in Gabon (7) -- were among the 10 most expensive cities.

Three Asian cities -- Tokyo, Osaka (6) and Hong Kong (tied at 8) -- were in the top 10, along with the European centers Moscow (4), Geneva (5), Zurich (tied at 8) and Copenhagen (10).

"Our cities are selected based on requests from our multinational clients," Mercer senior researcher Nathalie Constantin-Metral said in a statement with the survey.

"We've seen demand increase for information on African cities from across the business spectrum -- mining, financial services, airlines, manufacturers, utilities and energy companies."

Seven Chinese cities appeared in the 2010 rankings, highlighting the commercial importance to multinationals of locations other than just Beijing, Shanghai and Hong Kong.

The other most expensive cities in Europe were Oslo (11), Milan (15), London and Paris (both 17). The least expensive city in Europe was Tirana (200) in Albania.

Tel Aviv (19) was the most expensive city in the Middle East, followed by Abu Dhabi (50) and Dubai (55). Tripoli (186) in Libya was the least expensive Middle Eastern location.

"Accommodation costs have continued to decrease in Abu Dhabi and Dubai, driving down the cost of living for expats," Constantin-Metral said.

Brazil's commercial capital Sao Paulo (21) was the most expensive city in all of the Americas, a result of the strengthening of the real currency against the dollar.

In the United States, New York (27) was the most expensive city, followed by Los Angeles (55). Washington, DC, ranked 111 and the least expensive US city was Winston Salem (197).

Vancouver (75) was the most expensive Canadian city, followed by Toronto (76) and Montreal (98). The capital Ottawa (136) was the least expensive.

"The weakening of the US dollar against a number of other currencies, combined with a decrease in the cost of rental accommodation, has pulled US cities down the rankings," Constantin-Metral said.

In South America, Brazil's Rio de Janeiro (29) was the second most expensive city, followed by Havana (45), Bogota (66) and the Brazilian capital Brasilia (70).

Buenos Aires ranked 161 and Nicaragua's Managua (212) was the least expensive city in South America.