More than 400,000 people left homeless by Hurricane Katrina will remain in hotel rooms beyond the Oct. 15 deadline set for their relocation, the Red Cross and the Federal Emergency Management Agency said yesterday, extending a program that is costing an estimated $8.3 million a day.

The agencies said the program, which is in effect in 48 states, with most rooms clustered closest to the devastated area, would be extended indefinitely.

The hotel program had been established as a temporary measure, but efforts to house hurricane evacuees in trailer homes, on cruise ships or in market-rate apartments have largely failed. Instead, people have migrated from shelters into hotel rooms that are arranged for by the Red Cross and paid for by the federal government.

The Red Cross said that as of Sunday night, 438,030 people were living in 141,300 rooms, a number that has nearly doubled in the past two weeks. In Washington, the Red Cross this week placed the last 50 evacuees who had been living in the D.C. Armory in area motels.

"We're trying to make sure no one falls through the cracks," said Mary-Margaret Walker, a FEMA spokeswoman, who confirmed that the program would continue beyond Oct. 15 and that no new end date had been set.

"Our understanding is that the motel program will continue until a decision is made by FEMA on other alternatives. . . . We were not given an end date," said Carrie Martin, spokeswoman for the Red Cross. Martin said an agreement between the two bodies on extending the program was awaiting final approval last night.

The hotel program was conceived in the days immediately after Katrina. With shelters filled to bursting, many evacuees found refuge in motel rooms and were rapidly running out of money to pay their bills. The Red Cross, which underwrites hotel costs in smaller crises, asked FEMA to bankroll limited hotel stays for evacuees. FEMA agreed.

If the hotel plan had ended as scheduled Oct. 15, it was projected to have cost as much as $168 million.

Rooms in the program average $59 a night and are paid for through Wichita-based Corporate Lodging Consultants, which more typically books accommodations for Red Cross volunteers and staff. FEMA has agreed to reimburse the Red Cross for the room costs.

"It's just across the board just about any kind of hotel chain you can think of is represented -- a lot of Holiday Inns, a lot of Choice hotels, Best Westerns," said Tim Downs, the executive vice president of operations for Corporate Lodging Consultants.

Although most rooms are in mid-line or economy hotels, "the Red Cross told us not to put any caps on room rates because in certain states there were just no rooms," said George Hansen, the company's chief executive. "We deal with the American Red Cross; we don't deal with FEMA."

About 70 percent of the rooms are in Louisiana, Alabama, Texas, Mississippi and Georgia, Hansen said. "It's our understanding we've been averaging about three people and a fraction per room," he said.

Last week, Hansen predicted that the program would probably have to be extended. He said that, if asked, the company could try to help move evacuees into alternate housing, but "I don't see how that could happen by October 15. They'd have to come up with a . . . lot of apartments in 16 days."

If the program were to continue indefinitely, its administration could run counter to the Red Cross's mission of providing immediate disaster relief, not long-term housing.

"We are still administering the program at this time," Martin said. "But we are in discussions with FEMA as to when and if a transition in administration will occur."

Staff writer Spencer S. Hsu contributed to this report.