NEW YORK — The weakening dollar has caused many problems for consumers, but it may also be providing the fuel for one unintended — and very welcome — benefit: a rally in the struggling housing market driven by foreign investors.

For an individual or developer trying to sell a home, interested buyers are just as likely to already have a place in London or Paris as they are to be first-timers new to the market.

The theory goes that foreign investors step in and replace first-time homebuyers who have been squeezed out of the housing market during the recent downturn. These new investors in turn allow current homeowners to sell and trade up to larger homes.

That will help restart owners moving up the housing ladder, a process that had been key to economic growth in recent years.

Some mortgage brokers are already seeing a boost in inquiries about buying property from overseas. Dan Green, a certified mortgage planning specialist and author of www.TheMortgageReports.com, said the number of inquiries he's received from outside the U.S. is probably five to 10 times larger than it was a year ago.

A boost in the number of homebuyers would provide needed relief for the beleaguered housing market.

Home sale prices fell every month in 2007 through August, according to the S&P/Case-Shiller index. Existing home sales have declined for eight straight months through September, according to the National Association of Realtors.

As the housing market has plummeted, the dollar has also sunk to record lows compared to other currencies, such as the euro, meaning more spendable cash in the U.S.

"The dollar is on sale," said Susan Wachter, a professor of real estate at the Wharton School at the University of Pennsylvania.

Today, a foreign buyer would need only 34,100 euros to make a $50,000 down payment on a house. At the beginning of the year, the same buyer would have needed 37,920 euros to make the same down payment.

For investors from countries like Ireland, the exchange rate is providing a boost in spending power, said Phillip Hegarty, the sales director for Castleroc Estates, a Dublin, Ireland-based firm that works with Irish investors to buy residential and commercial real estate in the United States.

"It's an enticing investment," Hegarty said.

Hegarty said there is plenty of demand for investment in locations like Chicago and New York, and often that demand exceeds supply.

But New York and Chicago are not the only locations likely to provide popular options for foreign investors. Places like Florida and California are likely to see a surge in foreign investment.

"In a market with great turmoil, (the weak dollar) is one factor supporting some key markets," Wachter said of the weakening dollar.