LOS ANGELES (AP) — 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 Tuesday.

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, Calif.-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.

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 into an affordable loan.

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 notice of default, 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.”

The U.S. House passed a bill last week that would offer government insurance on $300 billion in new mortgages to refinance loans for an estimated half-million borrowers facing foreclosure, particularly those who now owe more than their houses are worth because of declining values.

House lawmakers also passed a bill that would send $15 billion to states to buy and fix foreclosed homes.

Still, should the homeowner aid package clear the Senate, it faces a potential hurdle in the White House, which has threatened to veto the plan, arguing it’s too risky and amounts to a lender bailout.

Even if a legislative compromise is reached, it could come too late for homeowners with adjustable-rate mortgages scheduled to reset to higher rates this month and the next.

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.