Scores of area nonprofit agencies that serve the homeless are feeling uncertain about their futures in the wake of news that an annual downtown walkathon sponsored by troubled mortgage giant Fannie Mae will end after this year’s Nov. 19 event on the Mall.

Fannie Mae, which has suffered since the 2008 economic meltdown, announced quietly in June plans to replace the big walk on the Mall with local mini-walks, a move that agency spokeswoman Amy Bonitatibus said is an expansion of the program. But many of the nonprofit agencies that provide services to the Washington area’s nearly 12,000 homeless people say they are concerned that the smaller walks won’t raise the same amount of money or public awareness as a big national Mall event.

“It was the largest event locally that kept homelessness in the public eye,” said Michael Ferrell, executive director of the Coalition for the Homeless. “I certainly think mini-walks are great. I just think the larger walk on the Mall is better.”

Bonitatibus insisted that the new model for the Help the Homeless program “has already demonstrated a higher return on public participation and raising funds.”

Last year, more than 100,000 people joined in 715 mini-walks in the Washington area, raising $1.5 million after expenses, and the downtown walkathon brought together 14,000 people and raised less than $1 million, Bonitatibus said.

It’s no secret that the mortgage agency has struggled since the 2008 economic downturn, and the higher costs of staging an event downtown contributed to the decision, Bonitatibus acknowledged. But Fannie Mae “will continue to administer registration and logistical details” for the mini-walks.

Some of the agencies that help the homeless, although grateful for Fannie Mae’s support, expressed trepidation about the change.

“We hope that part of it will remain intact,” said Jean-Michel Giraud, executive director of the Community Council for the Homeless at Friendship Place, which received $20,000 last year from the event. “A lot of the money we make is earned through special bonuses, so we get to leverage money not only the walkers put in, but money from Fannie Mae, as well. ”

Kristin Valentine, development director at Bread for the City, said some of its sponsors prefer to contribute through the walkathon. “My hope is the majority, if not all, will continue to lend us their support,” she said.

The Help the Homeless program has been an important event in the Washington area since 1988. It has raised $85 million for the service providers since its start, according to the Fannie Mae Web site. Because it is scheduled for the weekend before Thanksgiving, people often are in a charitable mood, and tens of thousands of people typically turn out.

Fannie Mae has been “such an important player in highlighting homelessness as an issue,” said Christopher Fay of Homestretch in Falls Church, which typically reaps $50,000 to $70,000 from the walk.

“It was very well placed strategically in terms of the calendar, and they bring out thousands and thousands of people,” Fay said. “We don’t really have a source to replace it. . . . It’s possible it will work out well, but it’s hard to calculate.”

Mary Agee, director of Northern Virginia Family Service in Oakton, said the reorganization of the large walkathon into numerous smaller ones will affect agencies differently, depending on their financial setup.

“As a suburban organization, most of our support and corporate support come not from the walk downtown but from little mini-walks,” she said. “Some groups rely on the large corporate sponsorships from the [Mall] walk. . . . The usefulness of it is there’s a focal point.”