The University of Chicago now has the largest single gift ever received by a Chicago area school -- $100 million -- and that's good news for students like Zainab Raji.

Raji might have to take out loans to cover the more than $47,000 in tuition and living costs to attend the U. of C. next year. But beginning in the fall of 2008, because her mother's income is less than $60,000, she won't have to take out any other loans for the rest of her schooling.

For all students in that income group, the donation will cover with grant aid what students in the past would have had to take a loan to cover.

"It will definitely help me a lot,'' said Raji, 19, of Rogers Park. "That was the biggest concern in deciding whether to come to this school, the loans and the finances.''

The U. of C. is hoping the new Odyssey scholarships will encourage even more students from low-and middle-income families to come to Hyde Park.

President Robert Zimmer said the school needs those students on campus to ensure it can continue the "rigorous inquiry'' it's known for.

The $100 million donor, a U. of C. graduate who asked to remain anonymous, said he wanted to ensure all students could have access to a top-notch school and be able to follow whatever path they choose.

"I give this gift in the hopes that future generation of students will not be prevented from attending the College because of financial incapacity and may graduate without the siren of debt distracting them from fulfilling unremunerative dreams,'' the donor said in a statement released by the school.

The gift should help about one-quarter of undergraduates, or about 1,200 students each year, who now finish with more than $17,000 in debt. Those in families with earnings between $60,000 and $75,000 will see their loans cut in half.

The school has undergone several efforts to increase diversity on campus in recent years, resulting in record levels of underrepresented minorities on campus.

But like many Ivy League schools, economic diversity remains elusive at U. of C., as just 12.2 percent of students come from low-income families who qualify for Pell grants, far lower than the national average. Nearly half the student body comes from the top-fifth of income earners.

"It's very hard to break through the assumption of unaffordability,'' said college enrollment dean Michael Behnke, who sees the scholarships as a powerful recruiting tool.

The school released few clues about the donor, but said he came from a "modest" background and graduated in the 1980s, which would put him on the younger side for such a big benefactor. They would not say whether he was a local area resident or not, or how he earned his fortune.

However, John Boyer, dean of the liberal arts college, said the donor really enjoyed classes like Greek literature, which were part of the university's core curriculum.

The U. of C. "had a profound effect on my life and in particular on allowing me to survive untold failures and persevere in mad adventures that have rewarded me with the financial resources to make this gift,'' the donor's statement said.

The university declined to reveal just what those adventures were.