Canadians are flocking to snatch up property in the U.S. as a result of affordable house prices and attractive exchange rates, the National Association of Realtors says.

Since May 2007, NAR estimates that between 150,000 and 190,000 homes in the U.S. were bought by foreign nationals.

This year, Canada replaced Mexico as the country with the largest share of foreign buyers in the U.S., with the percentage of Canadian buyers doubling to 23.5% from 11% last year, NAR said in its 2008 Profile of International Home Buying Activity survey. The UK came in behind Canada, followed by Mexico, China, India and Germany.

"Many international buyers recognize that real estate is an excellent investment and are drawn today by abundant inventory, low interest rates and a softer dollar," said NAR president Richard F. Gaylord. "These conditions allow them to own their own piece of the American dream."

Gaylord said foreign exchange rates have helped make U.S. homes more affordable for foreigners, particularly in Florida and Arizona. He noted that the euro has surged in value 24% against the U.S. dollar over the past two years.

Single-family vacation homes at an average price of $297,400 were the most popular purchase for international buyers. The most popular states for purchases were Florida, California, Texas, New York, Washington and Nevada, NAR said.

The NAR survey found four in 10 foreign buyers paid for their purchases in cash, compared to 7% of domestic U.S. buyers. It also found that the average international buyer stayed at their U.S. property for 2.6 months during the year.

Purchases by international buyers also tended to be more expensive, with 14% of properties sold valued at $750,000 or more.

The 2008 NAR Profile of International Home Buying Activity survey is based on responses from approximately 4,000 Realtors who serve foreign buyers.

By Stephen Huebl and edited by Sarah Sussman