Just as the housing market is showing signs of life, here comes another real-estate crisis.

Squeezed by plunging rents, empty storefronts, the credit crunch and a dearth of buyers, a growing number of commercial property owners are defaulting on their loans, which could unleash a new wave of bank failures and slow the region's economic recovery.

``What we're seeing so far in commercial real-estate [foreclosures] is just the tip of the iceberg,'' said attorney Lee D. Mackson, who represents creditors who filed a foreclosure suit against Biscayne Landing, a stalled project on Biscayne Boulevard in North Miami. ``There's going to be a lot more.''

Florida's home-grown community banks are heavily into commercial real-estate loans -- for office buildings, shopping centers, hotels and condos.

An exclusive analysis for The Miami Herald found that Florida banks have twice the proportion of commercial loans in their portfolios as banks outside the state.

As a result, Florida banks may have to weather the worst of the commercial real-estate meltdown.

A major sign of the festering problem came on Friday, as federal regulators seized Chicago-based Corus Bank, which has been a big lender in South Florida. The bank was brought down by heavy lending in commercial real estate and construction.

The potential impact of the downturn goes far beyond the individual tragedy of a lost business or the jobs that disappear when a single project fails.

Anemic banks are in no condition to lend. And solid banks and other lenders may become even more wary of providing money to start new projects or even refinance loans as they reach maturity, as is common practice.

For consumers, mortgages, home equity loans and lines of credit could dry up even more.

``It's another pretty heavy hit to an already hard-hit banking sector,'' says Sean Snaith, an economist and director of the Institute for Economic Competitiveness at the University of Central Florida. Commercial real-estate problems, he says, ``could prolong the credit crisis and make it difficult for all sorts of borrowers to get the loans they need -- consumers, homeowners and small businesses.''

According to the analysis by Charlottesville, Va.-based SNL, a data-crunching firm, more than 53 cents of every dollar loaned by Florida-based banks goes for commercial real estate, compared with 24 cents per dollar among other U.S. banks.

At mid-year, 11.2 percent of the commercial real-estate loans at Florida banks were delinquent, compared with 7.5 percent at banks outside Florida. And Florida banks have far less set aside to absorb bad loans.

``We not only see `For Sale' and `Foreclosure' signs in our neighborhoods, but `For Lease' and `Vacancy' signs along Dixie Highway,'' says Ken Thomas, a Miami bank analyst. ``Prime corner and other retail locations in the best shopping areas from Dadeland to Aventura to Boca are now vacant.''

To be sure, the nation's biggest banks and Wall Street are also facing a potentially heavy toll from the commercial real-estate downturn.

Among the prominent projects tangled in recent foreclosure suits are the Las Olas Centre in downtown Fort Lauderdale and Biscayne Landing, the latter envisioned as a massive residential and commercial project that was to be the key to revitalizing the city of North Miami. Except for two soaring towers, Biscayne Landing never got off the ground. Instead, it ended up as a bad debt included in securities sold on Wall Street.