The troubled AmeriCorps program would get $100 million to restore 20,000 volunteer slots under a measure approved yesterday by the Senate Appropriations Committee.

The money, if approved by Congress and signed into law by President Bush, would rescue hundreds of service programs from unexpected federal funding cuts last month that local leaders said would force them to trim back sharply on staff or close down entirely.

"This is a big victory for America and AmeriCorps," said Alan Khazei, chief executive officer of City Year, a 15-year-old AmeriCorps program that recruits 17- to 24-year-olds for a year of community service in 12 U.S. urban areas.

When national AmeriCorps leaders announced an 80 percent cutback last month in the program's largest category of volunteers, Khazei feared that seven of his group's 13 programs would have to close. If the $100 million goes through, all would stay open, he said yesterday.

"It shows that the leaders of the Senate really care about what happens to programs at the grass-roots level," Khazei said. "They've heard the need and they've responded in a powerful, bipartisan way. They want to support young people's efforts to serve their country, and they are not going to let this idealism go to waste."

Rob Waldron, chief executive of Jumpstart, a Boston-based nonprofit that recruits college students to work with children in Head Start programs, said his organization would enjoy a similar reprieve if the funding goes through.

"It's a wonderful day, in Jumpstart's case, for the children we serve," Waldron said. "It means that programs are no longer going to close, if this legislation passes. . . . We know the president is committed to AmeriCorps and national service and are confident he will show support for this legislation."

AmeriCorps volunteers serve 20 to 40 hours a week and provide such services as home-building, literacy coaching and cleaning parks and streams. Some volunteers get modest living stipends, but all are eligible for $4,725 grants to pay for college or graduate school, or to repay student loans.

The Clinton-era community service program -- which Bush has repeatedly praised and promised to expand -- indicated in May that it would not be able to fill more than half of its 50,000 volunteer slots in the current fiscal year. Administration officials have attributed the trouble to complex accounting and management problems at the federal Corporation for National and Community Service, the parent agency for AmeriCorps, as well as cuts in congressional funding.

Congress last month approved legislation, sponsored by Sens. Christopher S. Bond (R-Mo.) and Barbara A. Mikulski (D-Md.), that granted AmeriCorps more accounting flexibility and helped reduce damage to volunteer rolls. AmeriCorps officials said they would soon announce more grants. But AmeriCorps advocates said that wasn't enough, and called for Bush and Congress to pass as much as $200 million in new funding.

The move yesterday to insert $100 million into the supplemental appropriations bill was sparked by Mikulski but drew key bipartisan support from Bond and Sen. Ted Stevens (R-Alaska), the chairman of the Appropriations Committee.

Lindsey Kozberg, an administration spokeswoman, did not respond to a telephone call and an e-mail seeking comment on the committee action. Bush has said he wants to expand AmeriCorps to 75,000 volunteers next year but has been criticized for failing to put political muscle behind his rhetoric in seeking funding for the program.

The money approved by the Senate committee should enable AmeriCorps to reach a full enrollment of 50,000 volunteers this year, Mikulski said. She said trying for $200 million would have been too risky.

"I was worried that if we went for pie in the sky, we could get crumbs," she said. "I went for what I knew we could get with a bipartisan coalition."