Virginia officials formally acknowledged today that black enrollment at several of the state's traditionally white schools is falling significantly short of goals established under a three-year federal desegregation plan.

"Competition for black students is very, very fierce," said Barry M. Dorsey, an associate director of the Council of Higher Education, the governing body for the state's colleges and universities.

The council released a report today that confirmed news stories that said both the University of Virginia at Charlottesville and the Virginia Polytechnic Institute and State University at Blacksburg met only about half of their goals in enrolling first-time or transfer students who are black. George Mason University in Fairfax met its goal of 203 new black students.

Overall, Dorsey said, the state appears to have met about 80 percent of its goals, but said that is largely attributable to increases of black students at other four-year colleges and enrollments of whites at the state's two traditionally black schools.

Dorsey stressed that today's figures are "very, very preliminary" and noted that the schools will be able to count subsequent enrollments this fall and during the second quarters and semesters.

The desegregation plan is the product of a 1978 agreement with the U.S. Department of Education's Office of Civil Rights in which the state promised to make a major effort to integrate its 13 four-year colleges and its community colleges.

The agreement was renegotiated last year by the administration of Gov. Charles S. Robb after the state failed to make substantial progress toward its 1978 goals.

Last spring, the rights office generally praised the state's initial progress under the renegotiated agreement. Officials said it was too early to comment on this year's efforts.

In addition to enrolling more black students, the three-year plan which ends after the 85-86 school year, includes stepped-up efforts to hire more black faculty members and establishes programs to encourage blacks in state high schools to take college preparatory courses.

Dorsey said the state is making significant progress in those areas.