IRVINE, Calif. – The number of U.S. homeowners facing foreclosure rose 36 percent in August from their July level, as rising interest rates continued to squeeze holders of adjustable-rate mortgages (ARMs), industry analyst RealtyTrac Inc. said today in its monthly report. Compared with August 2006, foreclosures more than doubled, rising 115 percent.

Overall U.S. foreclosure filings last month – including default notices, scheduled auctions or bank repossessions – totaled 243,947, the highest in the three years covered by RealtyTrak records. But, the company noted, a single home in default may be counted twice or even three times in that total if it is the subject of more than one legal filing in a month.

The highest rate was in Nevada, with one filing for every 165 homes – triple the national average of one filing for every 510 homes. California followed at No. 2, with one filing per 224 households, and Florida was No. 3, with one filing per 243 households.

Rhode Island ranked 24th nationwide with one filing for every 1,207 homes, an increase of 121 percent from July, RealtyTrak said, while Massachusetts came in at No. 12 with one filing for every 594 homes, a 2.3-percent decline from its rate in July.

“The jump in foreclosure filings this month might be the beginning of the next wave of increased foreclosure activity, as a large number of subprime adjustable rate loans are beginning to reset now,” CEO James J. Saccacio said in a statement.

Ominously, the month saw lenders send a record 108,716 notices of mortgage default, the first step in the foreclosure process, RealtyTrac said. The numbers were highest in California, with 41,714 new foreclosures, and Florida, with 26,203, the company said.

Subprime loans often have “teaser” rates that may double at the end of two or three years, Rick Sharga, executive vice president of marketing for RealtyTrac, told Bloomberg News.“There are lots of people who bought homes they could only afford at the ‘teaser’ rates and now have very few options,” he said.

RealtyTrac Inc., based in Irvine, Calif., is a publisher of data and advice for real estate markets nationwide. To learn more, visit www.RealtyTrac.com.