Microsoft Corp. Chairman Bill Gates today pledged to spend $1 billion over the next 20 years giving college scholarships to thousands of academically talented but financially needy minority students across the country. The gift would be the largest philanthropic gesture ever in education.

Gates, the world's wealthiest person, has never made a bigger contribution to any single cause and this one is almost without rival in the nation's history. It equals the amount that media mogul Ted Turner committed to United Nations humanitarian programs two years ago.

In an announcement this morning from Seattle, Gates said he is creating the scholarships because he believes that too many minority students are not reaching or finishing college -- and in particular pursuing degrees in medicine, science and technology -- strictly because the expense of doing so is often too great.

"This country is in an incredible time period. The advances in technology are really quite breathtaking," Gates said. "Is everybody getting a chance to benefit? The answer is really no."

With the gift, Gates is taking aim at one of the most intractable problems in higher education: improving access to college for minorities and closing the gap in academic achievement that often still exists between minority students and white students on campuses. The proportion of minorities enrolling in college is rising, as is federal aid for tuition. But for many, earning degrees, especially advanced ones, is still difficult.

For Gates, the billion-dollar pledge also could serve other purposes. Some critics have charged that he has not been devoting enough of his staggering wealth -- his net worth is estimated at nearly $90 billion -- to charities.

Until now, Gates's largest donation to one cause was $100 million to help immunize young children from disease in developing countries around the world.

Others also contend that Gates's public image has been badly bruised during Microsoft's long and bitter antitrust battle with the federal government.

But supporters of Gates said today that his motives are genuine. "This is not a game," said Dorothy Ridings, president of the Council on Foundations. "They are walking the talk."

Higher education officials called Gates's gift astounding in its size and purpose and said it could have a profound effect on the advancement of minorities in fields where their numbers are now quite small.

"This is as big as it gets," said William H. Gray III, president of the United Negro College Fund, which will help administer the scholarship program from its headquarters in Fairfax County. "It breaks every kind of philanthropic record, and we think it could really transform the educational landscape in this country."

Gates intends to launch the scholarship program next fall. As part of it, at least 1,000 high school seniors per year for the next two decades will have their unmet financial needs covered at the university of their choice. Gates said he expects to commit $50 million annually to the initiative, all of it from the Bill and Melinda Gates Foundation, which Gates and his wife established this year. It has about $17 billion in assets and is the largest in the country.

The foundation already has pledged several hundred million dollars to an assortment of educational causes nationwide, such as improving Internet access and expanding computer hookups at needy public schools -- initiatives that some skeptics have questioned as self-serving.

The latest education gift dwarfs all others to that cause. It is twice the size of the $500 million that billionaire publishing heir Walter H. Annenberg began giving in 1993 to help struggling big-city school districts across the country improve student achievement.

To be eligible for the Gates scholarships, students must have at least a 3.3 grade-point average and demonstrate significant economic disadvantage. They will have to write an essay about their life goals and commit to performing community service. Students also must be nominated for the award by a principal, teacher or community leader. Scores on college entrance exams will not be used in the selection process.

Those chosen for the program, which will be known formally as the Gates Millennium Scholarships, will have to remain in strong academic standing throughout college. The size of the scholarships will vary according to the needs of individual students, but the assistance is good for four years. And Gates has vowed to extend the scholarships of students who then pursue advanced degrees in fields such as math, science and education.

Sara Martinez Tucker, president of the Hispanic Scholarship Fund, praised the gift as a potentially powerful tool to expand the educational opportunities of minority students at a time when the job market is demanding ever more academic training.

Only about half of the nation's Hispanic students now earn high school diplomas, Tucker said, and only about one-third reach college. And only about 10 percent of those students get degrees.

"This will help us meet the needs of our community more, better and faster," she said.

Gray said in an interview that today's announcement was the culmination of two years of meticulous planning by the Microsoft co-founder and his wife. He said the idea began to bloom as the three of them drove one day along highways in Alabama, through impoverished towns that were the cradle of the civil rights movement, bringing gifts of new computer technology to public libraries that badly needed it.

"We started talking about the problem of educational access in the country, and how often the biggest barrier is not lack of aspirations or lack of talent in the classroom," Gray said, "but just money."

Special correspondent Cassandra Stern contributed to this report.

Gates's Gifts

These are among the largest gifts from the Bill and Melinda Gates Foundation:

$1 billion over 20 years in aid to minority students, administered by the United Negro College Fund.

$200 million to bring computers and training to libraries in low-income communities.

$100 million to bring new vaccines to children in the developing world.

$50 million to Columbia University's School of Public Health for prenatal care in developing countries.

$50 million for research on a malaria vaccine.

$25 million to the International AIDS Vaccine Initiative, which is seeking an AIDS vaccine.

$20 million to Johns Hopkins University's School of Hygiene and Public Health for reproductive health in developing countries.

$20 million to Duke University for an interdisciplinary scholars program.

$10 million to the World Health Organization for research on male responsibility in human reproduction.

SOURCE: Bill and Melinda Gates Foundation