LOS ANGELES — More U.S. homeowners fell behind on mortgage payments last month, driving the number of homes facing foreclosure up 65 percent versus the same month last year and contributing to a deepening slide in home values, a research company said Monday.

Nationwide, 243,353 homes received at least one foreclosure-related filing in April, up 65 percent from 147,708 in the same month last year and up 4 percent since March, RealtyTrac Inc. said.

Nevada, Arizona, California and Florida were among the hardest-hit states, with metropolitan areas in California and Florida accounting for nine of the top 10 areas with the highest rate of foreclosure, the company said.

Irvine-based RealtyTrac monitors default notices, auction sale notices and bank repossessions.

One in every 519 U.S. households received a foreclosure filing in April. Foreclosure filings increased from a year earlier in all but eight states.

In Ventura County, foreclosure filings totaled 731 in April, down 18 percent from March but up 78 percent for the same month last year. There were 587 default notices, 93 auction sale notices and 51 bank repossessions in April, according to RealtyTrac.

One in every 370 Ventura County households received a foreclosure filing.

Nationwide, the combination of weak housing sales, falling home values, tighter mortgage lending criteria and a slowing U.S. economy has left financially strapped homeowners with fewer options to avoid foreclosure. Many can't find buyers or owe more than their home is worth and can't get refinanced.

Efforts by government and the mortgage industry to stem the tide of foreclosures aren't keeping up with the rising number of troubled homeowners.

The April data show nearly half of the properties received an initial default notice, suggesting many homes were new entrants to the foreclosure process.

"We're still sitting at roughly the same percentage of loans handled in any way successfully as we were a year ago, and the volume (of foreclosure filings) still keeps going up," said Rick Sharga, RealtyTrac's vice president of marketing. "It's apparent that what they've tried so far isn't working."

More than 1 million home foreclosures are forecast for 2008. "It doesn't look like the volume is going to slow down any time soon," Sharga said.

More than 54,500 properties were repossessed by lenders nationwide in April. In all, about 2 percent of U.S. households were in some stage of foreclosure during the month, RealtyTrac said.

— Star staff contributed to this report.