After seven years of nonstop construction, skyrocketing rents and sales prices, and a seemingly endless appetite for luxury housing that transformed gritty and glamorous neighborhoods alike, the credit crisis and the turmoil on Wall Street are bringing New York’s real estate boom to an end.

Single-family home prices in 20 cities fell 16.3% in July, the fastest pace on record - even before Wall Street woes shifted into high gear. And New York City was not immune. Metro-area prices fell 7.4% from July 2007, according to Standard & Poor's Case-Shiller home price index.

Developers are complaining that lenders are now refusing to finance projects that were all but certain months or even weeks ago. Landlords bewail their inability to refinance skyscrapers with blue-chip tenants. And corporations are afraid to relocate within Manhattan for fear of making the wrong move if rents fall or a flagging economy forces layoffs.

“Lenders are now taking a very hard look at each particular project to assess its viability in the context of a softening of demand,” said Scott A. Singer, executive vice president of Singer & Bassuk, a real estate finance and brokerage firm. “There’s no question that there’ll be a significant slowdown in new construction starts, immediately.”

Examples of aborted deals and troubled developments abound. Last Friday, HSBC, the big Hong Kong-based bank, quietly tore up an agreement to move its American headquarters to 7 World Trade Center after bids for its existing home at 452 Fifth Avenue, between 39th and 40th Streets, came in 30 percent lower than the $600 million it wanted for the property.

To be sure, the worst pain was felt in the suburbs. In Manhattan, foreign buyers were still spending heavily on luxury apartments during the summer - along with Wall Streeters who still had high-paying jobs. "There's no question that the city itself held up well in July," said Bill Keleher, CEO of Prudential New Jersey Properties.

A 40-story office tower under construction by SJP Properties at 42nd Street and Eighth Avenue for the past 18 months still does not have a tenant.

But there are fears that Wall Street's meltdown will drag the city's housing market into similar trouble. With credit tightening and thousands of Wall Street jobs evaporating, some would-be buyers are dropping out of purchase deals because they can't get mortgages. Others are showing up at open houses but not making purchase offers.

First indications of how the Manhattan apartment market is faring will come later this week, when real estate firms plan to release third-quarter sales figures.

And the law firm of Orrick, Herrington & Sutcliffe last week suddenly pulled out of what had been an all-but-certain lease of 300,000 square feet of space at Citigroup Center, deciding instead to extend its lease at 666 Fifth Avenue for five years, in part because they hope rents will fall.