As he prepared to attend Sunday's national summit on voluntarism, President Clinton on Saturday unveiled a $2.75 billion program aimed at mobilizing a million Americans to pick up a book and teach a child to read.

In his weekly radio address, Clinton said he would send to Congress on Monday a five-year plan that would pay for 25,000 reading specialists and tutor coordinators to lead the massive volunteer effort."All of us can help," said Clinton, urging potential volunteers to call 1-800-USA-LEARN. "All you have to do is roll up your sleeves, sit with a child and open a book together. Remember, you'll be doing more than just reading. You'll be writing an exciting new chapter in America's progress."

Clinton announced the reading initiative last summer, but the details were not available until Saturday. The program, with a price tag of $460 million in the 1998 fiscal year, would attempt to provide reading help before and after school to 3 million children in 20,000 schools.

To show the depth of the need, the White House noted that 40 percent of fourth-graders scored below the basic level on the 1994 National Assessment of Educational Progress. Administration officials also cited studies showing that students who cannot read well by the end of the third grade are more likely to drop out of school or underachieve.

The president's plan to show children the joys of a good book is just one of many volunteer initiatives organizers expect to emerge from the national service summit that opens Sunday in Philadelphia. The brainchild of the late Michigan Gov. George W. Romney, the summit is designed to foster a new volunteer spirit reaching businesses, community leaders and every American.

"Citizen service is neighbor helping neighbor," Clinton said in his radio address. "It's part-time volunteers and full-time community service workers. It's communities coming together to solve common problems. And it is an essential part of what it means to be an American."

The summit is expected to draw volunteer advocates from across the United States. To create a bipartisan spirit, Clinton will join former Presidents Bush, Carter and Ford at the kickoff. They will be joined by former first lady Nancy Reagan and retired Gen. Colin L. Powell, the general chairman of the event. The Presidents' Summit for America's Future is being held in Philadelphia to keep it away from the partisanship in the nation's capital.

"We're on the verge of a new century filled with promise and challenge, but to make the most of it, we must ensure that all our people and especially all our children, have the opportunity to reach their highest potential," Clinton said. "And we must understand that we can do that only if we all join hands, reaching across the lines that divide us to build one America together."