District high school graduates will be allowed to attend Maryland and Virginia colleges at in-state tuition rates under legislation approved yesterday by the House and sent to President Clinton.

The landmark program, widely supported by lawmakers of both parties and the District's top political and business leaders, significantly expands education choices for hundreds of college-bound D.C. seniors, probably starting next fall. It is a major part of a developing strategy to keep families of all income levels in the District and to attract families to the city.

"College-bound seniors in each of the 50 states have a vast network of state-supported institutions to attend," said Rep. Thomas M. Davis III (R-Va.), who introduced the legislation along with Del. Eleanor Holmes Norton (D-D.C.). "This bill seeks to level the playing field for D.C. residents."

Added Norton: "No longer will our youngsters alone be denied access to the array of higher education opportunities other Americans obtain as a matter of their citizenship in their states."

The Senate passed the measure Oct. 20. The Clinton administration strongly endorsed the bill, and the president is expected to sign it. The federal government will cover the difference between the out-of-state and in-state tuition, estimated at about $17 million a year. That money has been authorized and set aside in the federal budget for this fiscal year.

Though the program initially restricts students to Maryland and Virginia colleges--including historically black colleges and universities in both states--the bill gives Mayor Anthony A. Williams (D) permission to consider expanding the program to schools in the rest of the nation.

Such an expansion would largely depend on costs. Congress started with the idea that the program would apply to all 50 states but had to scrap that idea when the projected cost swelled beyond $17 million.

Instead, D.C. students attending public colleges and universities in Maryland or Virginia will receive grants of up to $10,000 a year--no more than $50,000 total--providing that they, like in-state students, meet the school's enrollment requirements. High school graduates must start college within three years after high school unless they first serve in the military, Peace Corps or AmeriCorps.

Seniors at D.C. public high schools will be eligible to receive another $2,000 a year in college grants--up to $10,000 total--through a private nonprofit called the D.C. College Access Program, which is raising money from corporations and foundations. That program is in six D.C. high schools this year, and there are plans to extend it to all 19 high schools next year when the federal program is launched.

Between the federal and private grant programs, "We should be able to send any D.C. public high school kid to college," said Argelia Rodriguez, executive director of the D.C. College Access Program. Washington Post Publisher Donald E. Graham is chairman of the access program's board.

Under the federal program, grants also will be awarded to D.C. students attending private colleges and universities in the region, but with more restrictions. Those who enroll in private colleges in the District or in Fairfax, Arlington, Montgomery and Prince George's counties or the cities of Fairfax, Alexandria or Falls Church could get as much as $2,500 a year, to a total of $12,500.

D.C. public high school seniors can qualify through the D.C. College Access Program for another $2,000-a-year grant to attend a private college or university in the two states. The bill provides $1.5 million to the District's own "state" school, the University of the District of Columbia, to strengthen programs there.