LAS VEGAS — For decades, this gambling center seemed nearly immune to the nation's economic swings. But these days, the city built on excess is seeing a troubling sign: moderation.

Gambling revenue and hotel occupancy are down. Resorts are slashing room rates and offering coupons or free nights. Casino operators are firing hundreds of workers, and their stock prices have plummeted since October. Credit is drying up for hotel and condominium projects planned before the slowdown hit.

Even those still coming to Las Vegas are spending less. Julia Lee, 27, of Los Angeles said she normally brings $10,000 here to play blackjack. As Lee picked up show tickets the other night, she said she had brought less than half that on this trip. "My parents are in real estate, and we're worried," she said.

So are this city's hoteliers, retailers, wedding-chapel operators and anyone else who depends on the extravagance of gamblers and tourists. The spending declines are relatively modest, a few percentage points here and there. But Las Vegas has a huge inventory of new casinos and hotels due for completion in the next few years, and a long national recession could send the city reeling.

The Vegas outlook would be far worse if not for foreign visitors. They are taking advantage of the low dollar to snap up goods that might cost twice as much in Europe.

But representing only 13 percent of visitors, foreigners can take up only so much slack. Deutsche Bank recently started foreclosure on a $760 million construction loan for the Cosmopolitan Resort and Casino, a partly built project in the heart of the Las Vegas Strip.

Crown Las Vegas, a bullet-shaped hotel and casino resort that was supposed to become the tallest building in the city, was scrapped a few weeks ago for lack of financing.

One of the most prominent Las Vegas casino operators, Tropicana Entertainment, said Monday it would seek bankruptcy protection.

Other multibillion-dollar Las Vegas projects are facing delays or have been put up for sale because of tightening credit and changing Wall Street perceptions about the city.

"In this market, it is not good business to be confident," said Jan Jones, a senior vice president at Harrah's Entertainment and a former Las Vegas mayor. "I've never seen an economy like this nationally. Nobody knows how deep what nobody wants to call a recession will go."

Historically, Las Vegas has been resistant to recessions, entering them later and exiting them sooner than the country at large. Gamblers, particularly high rollers, tend to play whichever way the economic winds are blowing.

But executives here worry this recession could be different from the last two — in 1990-91 and 2001 — when consumer spending was propped up by easy credit. Now credit is drying up. And high gas and food prices, declining home values and rising unemployment are keeping many Americans closer to home.

More important, over the last two decades Las Vegas has shifted from a destination dominated by gambling to one with more appeal to middle-class shoppers, diners, golfers and others who can afford brief splurges.

Whereas gambling represented 58 percent of revenue for Las Vegas Strip resorts in 1990, it represented only 41 percent of revenue in 2007, according to a Deutsche Bank report.

As gambling was legalized in more parts of the country in recent years, Las Vegas was forced to expand its own offerings. It worked, but it made the city more susceptible to recessionary declines in disposable income.

"Las Vegas is now as vulnerable as other communities," said J. Terrence Lanni, chairman of the board of MGM Mirage.

However, Lanni said he saw a silver lining to the downturn. He predicted that a large percentage of the 40,000 new rooms planned by 2012 will be put off, giving Las Vegas time to develop airport and other facilities to expand more smoothly.