The Irvine, Calif.-based real-estate research firm said there were 145 Hawai'i foreclosure filings last month, up 245 percent from 42 in the same month last year.

However, the company said the year-over-year change may have been inflated because of expanded data coverage for the state compared with a year ago.

Nationally, foreclosure filings rose 115 percent to 243,947 — the highest number of filings in a single month since RealtyTrac began issuing its reports in January 2005.

RealtyTrac said that given all the trouble with subprime lending, filings may be headed higher.

"The jump in foreclosure filings this month might be the beginning of the next wave of increased foreclosure activity," RealtyTrac CEO James Saccacio said in the report.

Foreclosures are rising because many consumers can't keep up with mortgage payments and face difficulty trying to refinance or sell their property as the housing market slows and prices in some areas drop. In many cases, defaults are rising because interest rates are resetting at dramatically higher rates for exotic loans heavily marketed to subprime borrowers over the last several years.

Hawai'i has maintained a relatively low foreclosure rate thanks in part to mostly stable home prices and a strong job market. Local lenders also say Hawai'i borrowers generally were more conservative, and didn't take out as many of the riskier loans compared with some Mainland markets.

Still, RealtyTrac data shows that Hawai'i foreclosure filings have risen in seven of the first eight months of this year compared with a year earlier.

RealtyTrac said Hawai'i's 145 foreclosure filings last month equated to one for every 3,387 households.

That was 10th-lowest among states, and compared with a national average of one filing per 510 households.

Nevada, where there were 6,197 August foreclosure filings, had the highest filing rate at one per 165 households. The lowest rate was in Vermont, where 11 filings equated to one per 27,940 households.

RealtyTrac's data is one of the better, though imprecise, indicators of how many homeowners are facing foreclosure.

The company counts a range of document filings in the foreclosure process, from default notices to auction notices and bank repossessions.

Because of the methodology, RealtyTrac's count can include more than one foreclosure filing on the same property. But the data also misses nonjudicial foreclosure notices that aren't recorded publicly, and situations in which homeowners in mortgage default are working with lenders in hopes of avoiding foreclosure action.