DALLAS -- We already know the number of foreclosures nationally is skyrocketing. Now there's a new trend in North Texas, and it comes as a big surprise to renters.

Right now in Dallas County, there are more than 3,500 foreclosed houses on the market. There are more than 2,700 in Tarrant County.

Some of those homes were occupied by renters when the foreclosures went down.

The Ederer family rents a house in Frisco. They moved in just a few months ago and were settling in. But two letters intended for the man who owns the house came in the mail and changed everything.

One letter was from a bank. It advised the homeowner he could "avoid foreclosure" by enrolling in a "homeowner assistance program."

Cord Ederer opened another letter from the Lakehill Homeowners Association. It asked for membership dues that hadn't been paid in two years.

Ederer said his landlord was supposed to be paying those dues, and now the family is worried.

"We're just waiting for a knock on the door and for somebody to tell us it's time to get out," said Ederer, a father of two.

Under Texas law, the homeowners association can foreclose on the house he is renting, and area realtors say that's happening a lot.

When banks foreclose, homeowners lose the home and renters have to go. Sometimes, there is no warning.

Ola Cole, who lives in Richardson, says this has happened to her twice.

She came home from work and discovered a note on her door from a bank, asking her to call them. Cole made that phone call and discovered her rented house was being foreclosed on.

She found another house to rent in Richardson, where it happened again.

"Where am I going to move?" Cole asked. "I've got to find me a place. It's not easy to just jump up and move."

Realtor Nelda Walker said this is happening too often across Dallas-Fort Worth.

"It makes me very upset when it happens to tenants," Walker said. "Then we've got to move them, and they've not got a clue. I wish they would give them the opportunity to say, 'I'm going into foreclosure, please keep your money. Don't make any more payments to me so you can rent something else.'"

As the economy continues to slide, Walker said she expects more foreclosures — and more renters who are out of luck.

E-mail sstoler@wfaa.com