The Maddens' cash-strapped Kansas City neighbors moved out last August, and the lender on the now-vacant house let it fall into disrepair. The pool is slime-green. The grass is knee-high.

"It's frustrating," Carrie Madden said. "It's an eyesore, and it sits right at the entrance to our neighborhood. It's not only a blight; it's unsafe."

Not what you would expect in a neighborhood of homes whose average value is about $280,000.

The house is a prime example of a little-reported but increasingly worrisome trend: lenders' delaying foreclosure on homes vacated by owners who can't make payments.

Maintenance stops, or it falls to local taxpayers.

"Someone has to maintain the property," said Nathan Pare, head of Kansas City's Dangerous Buildings Department. "If the owner surrenders the house, then it's up to the bank. But some banks aren't doing it."

Why foreclosures are being delayed is debatable. The trend runs counter to the assumption that banks want to get rid of distressed properties as soon as possible.

Kansas City officials say some lenders delay taking possession because they want to avoid paying taxes and upkeep. Legal aid lawyers say banks may be trying to hide steep losses that could attract regulators. Industry officials say lenders are swamped during these difficult times.

"I've not heard of any intentional acts," said Berry Laws III, a creditor's attorney who represents lenders in foreclosures. "There's just a glut. Lenders are overwhelmed with properties."

Whatever the cause, experts say the trend, which began around January, is spreading nationwide.

"There are more and more properties falling through the cracks," said Joe Schilling, a founder of the National Vacant Properties Campaign.

Usually, when a stressed homeowner falls behind in payments or surrenders the home to the bank, the lender forecloses to take back ownership and resells the house, often on the courthouse steps.

Kansas City officials rely on foreclosure records to determine the owner, to know who is responsible for a lack of upkeep, for trash removal, abatement or, in the case of abandoned properties, for sealing or demolition.

Now, increasingly, the city can't find the responsible owner. There's a past occupant, long gone, and a lender that hasn't filed a transfer of ownership.

In the last fiscal year, which ended April 30, the city sought to collect $1.4 million for mowing weeds, hauling trash, and boarding up or tearing down vacant houses.

The number of homes with ownership and futures in limbo in Kansas City alone is impossible to estimate. Lawyers with Legal Aid of Western Missouri are trying to compile at least a partial list. Jeff Williams said he was reviewing 200 vacant properties for possible action.

"If it's been sitting vacant for a sustained period of time, it represents a security issue for the people who live on those blocks," he said. "In the past, these lenders would turn these houses quickly. They're not doing that now. In some cases, a lender may start a foreclosure and then suddenly halt the proceedings and let the house sit."

Some wonder if the reason lies in regulations. Banks are required to keep a minimum capital reserve to ensure they can sustain heavy losses. But they've already lost billions of dollars. And foreclosing can cost a bank $15,000 or more.

John Meachem, a spokesman for the Mortgage Bankers Association, said lenders were applying a kind of triage to the crush of foreclosures.

Last month, the group reported that more than one million homes were now in foreclosure, the highest rate ever recorded. Meachem said lenders' efforts to help consumers who wanted to stay in their homes were coming "at the expense of maintaining vacant homes."

The root of the problem might be found in the go-go years of the housing boom, when mortgages became as complicated as sophisticated stock transactions.

Lenders made loans and quickly sold them off. Loans were chopped and packaged into securities and sold as investments. Thousands of investors became owners of a single home loan.

Large banks acted as mere trustees. For example, Deutsche Bank, a large European bank, is listed as the lender of record on more than 360 foreclosed loans in Kansas City's urban core. Bank spokesman John T. Gallagher said the institution, though listed on county records, holds no legal title of ownership.

"The trustee is not responsible for foreclosures or selling foreclosed property," he said.

Instead, he said, the decision whether to foreclose, to pay for upkeep, or to pay taxes rests with an initial lender or a service company hired to oversee the property.

Real estate experts say it can take months to determine the true lender or loan service, which may not be listed in court or county records.