Increasing numbers of foreigners calling Hong Kong home are lifting rental prices in the city's already expensive real estate market, pushing the city to become the most expensive place to rent high-end property globally.
According to ECA International, rents for an unfurnished luxury three-bedroom apartment in Hong Kong averaged $11,813 per month in the fourth quarter of 2011. That's up 15 percent on year, and one of the biggest increases in the region. The territory is followed by Tokyo, Moscow, New York and London.
"International assignee numbers in Hong Kong have increased again over the past two years, contributing to the demand for rental accommodation," said Lee Quane, Regional Director at Asia ECA International.
Quane tells CNBC that's put a lot of strain on the already limited supply of rental housing.
"People can less and less afford to actually purchase accommodation now, and that's actually kicking off, or I suppose reinforcing the rental market here. More people are actually renting, so therefore that's actually creating greater demand," said Quane.
Even with prices in the broader Hong Kong property market falling, Quane notes that the top-end of the market will hold up.
"The property market in Hong Kong, while it is volatile, still generally tends to be quite robust, particularly at the upper end of the market. So even if we may see, massive, or major falls in property prices or even rental values in the mass market section, we may not see it so much in that type of headline figure," he said.
Tokyo is the second most expensive city in top-end rentals, where three-bedroom apartment leases fetch an average of $9,450 a month. Singapore, with rental costs of $5,570 a month, ranks third in the region and ninth globally.
But Hong Kong falls from the top spot when rents in the lower end of its property market are factored in. When two-bedroom apartments in lower-cost areas are considered, for example, Hong Kong slips to the fifth place, with Tokyo becoming the most costly rental location.
Across Asia as a whole, rental prices for luxury three-bedroom apartments have gone up 5 percent in local currency terms over the last 12 months and 10 percent in U.S. dollar terms. Rents in the region now average $3,680, nearly 20 percent higher than the global average of $3,080.