NEW YORK - The days of oceanfront property as a good investment might be a thing of the past.

Some homeowners in California, Florida and the Southwest now face more than a 60 percent chance their property will be worth less in two years, according to a new study by a mortgage insurer. For Texans and Midwesterners, there is much less reason to worry.

The PMI U.S. Market Risk index, released Tuesday by PMI Mortgage Insurance Co., predicts a less than 1 in 10 chance of price depreciation in markets such as Dallas, Houston and Indianapolis. Pittsburgh is the safest, with a 6.4 percent risk that home prices will fall.

That's in stark contrast to the once-booming regions on the coasts. The index found that 15 of the nation's 50 largest metro areas have a greater than 50 percent chance of seeing price drops.

Eleven of those markets are in Florida and California, including Miami and Los Angeles. These are areas that enjoyed some of the largest price increases during the five-year housing boom ended nearly two years ago.

'What the markets with the greatest risk of decline have in common is a history of price volatility: rapidly rising rates of price appreciation above the long-term average followed by a recent sharp slowdown in the rate of appreciation,' said Mark Milner, PMI's chief risk officer.

The riskiest markets are Phoenix, Las Vegas, West Palm Beach and Riverside, Calif. - each with a greater than 60 percent chance of depreciation.

Not far behind in the second tier of risk are Orlando, Fort Lauderdale, Miami and the Tampa Bay area. Nationwide, the average chance of a price decrease in the 50 largest markets is 34 percent, PMI said. Boston and Washington are the riskiest markets in the East, with a 50 percent chance of decline. New York is safer, coming in near the national average

PMI's Risk Index estimates the probability that home prices will fall within the next two years but does not forecast the depth of any decline. Its calculations are based on first-quarter data on home-price appreciation from the Office of Federal Housing Enterprise Oversight, along with mortgage prices, labor market trends and housing demand in each market.

The company adjusted its statistical model to give more weight to recent volatility in home prices, which led in part to the increased risk scores in metro areas in the West and Southeast, PMI says.

Walnut Creek, Calif.-based PMI, a unit of residential mortgage insurer PMI Group Inc., typically publishes the index quarterly but skipped the spring reading because of the revision to its model.

The forecast for price declines in many major markets in the next two years comes with the housing market struggling with lower prices.

The median price for an existing single-family home fell 1.8 percent to $212,3000 in the first quarter, according to the National Association of Realtors. That was the third consecutive quarterly decline. Prices slid 2.6 percent in April, a record ninth consecutive monthly drop.

Home prices fall when the supply of available houses exceeds the number of buyers. That has been the case for more than a year, after builders spent lavishly to develop land in response to a surge in demand for homes that was exaggerated by speculative buyers.

Companies have curtailed building recently as they try to sell existing stock. In May, new-home construction fell 2.1 percent, mainly on weakness in the South and West, the Commerce Department reported Tuesday. That was the sharpest drop since a 13.9 percent slump in January.

Construction permits, an indicator of future activity, fell 1.8 percent, but Banc of America analyst Daniel Oppenheim said the drop was not enough to affect an upturn in prices.

'Lower construction is needed to work through the excess supply,' he said. Until that happens, he added, builders likely will continue to cut prices to increase sales, which will hurt prices for existing homes.

'Existing homes for sale will continue to sit on the market unless sellers cut pricing aggressively,' Oppenheim said.