Since 1980, the number of black undergraduates attending Maryland's colleges and universities on a full-time basis has fallen 16 percent, according to a recent report.

Educators said they believe the main reason for the trend is economic.

Officials said black students have been particularly hard hit by the higher costs of a college education and diminishing financial aid.

"Such a high percentage of our black students are in the lower income groups," said Joseph Popovich Jr., who directs planning and research for the State Board for Higher Education. "Financial aid means everything to them."

American Council on Education statistics indicate the funds the federal government provided for student aid, in constant dollars, dropped 19 percent between 1980 and 1984.

"It's a tough problem, because you're dealing with students who are in need of the opportunity," said Sheldon Knorr, state commissioner for higher education. "To tell them, 'Here's the action, but you can't afford it,' to me is really unconscionable."

State officials said the dwindling number of black applicants to Maryland schools has thrown off a five-year state desegregation plan that expired last year.

Two parts of that plan -- to enroll more black freshmen and curb the rate at which blacks drop out -- were not accomplished within the time frame.

"Unless we can improve the black college-going rate," said Hoke Smith, president of Towson State University, "it is going to be very difficult for any of us to meet the goal of the desegregation plan."

Officials said that if the plan is not successful, federal funds could be withheld from schools.