(Bloomberg News) Jason Haber, who runs a New York real estate brokerage firm, is struggling to find apartments to show a client who's in the market for a Manhattan home priced around $8 million.

Faced with a dwindling supply of luxury properties, Haber said his agents at Rubicon Property have resorted to mailing letters to 300 condominium and townhouse owners around the city to see if anyone might consider selling.

"That's not something you would do if the market was flush with high-end inventory," said Haber, co-founder and chief executive officer of Rubicon. "That's a sign of the times. This is a ready, willing and able buyer and we can't find the product for him."

International buyers seeking stable investments and "resolute" New Yorkers eager for deals at prices still in a post-recession dip have fueled a yearlong increase in sales of homes priced at $5 million and above, Haber said. The surge drove down the supply of Manhattan apartments for sale in that range last month to the lowest level for an October since 2007, according to StreetEasy.com, a property-listings website.

There were 832 homes on the market with asking prices of at least $5 million last month, compared with 862 in October 2010, 917 in 2009 and 909 in 2008, StreetEasy data show. In October 2007, near the real estate market's peak, there were 588 listings.

"Overall Manhattan inventory is shrinking," said Sofia Song, vice president of research at StreetEasy. "In the $5 million and up segment, it is specifically new-development inventory that is shrinking."

$10 Million Deals

Sales of Manhattan luxury apartments, defined as the top 10 percent of all condo and co-op transactions by price, jumped 17 percent in the third quarter from a year earlier, according to appraiser Miller Samuel Inc. and broker Prudential Douglas Elliman Real Estate.

Of the 311 sales in the category, 25 were priced at $10 million and above. That was the second-highest level since the 2008 collapse of Lehman Brothers Holdings Inc., surpassed only by the second quarter of this year, according to Jonathan Miller, president of New York-based Miller Samuel.

"It's been a good year, with fairly robust demand at the upper end of the market," Miller said in a telephone interview. "This wasn't unique to Manhattan. Across the region, we were seeing the high end seem to wake up."

Prices haven't returned to peak levels. The third-quarter median price in the top 10 percent of the market was $4.17 million, down 16 percent from the high of $4.99 million in the first three months of 2008, according to Miller.