Prince George's County should expand its popular magnet school system so that the special programs will be available to the children now in magnet classes as they move into higher grades, according to a citizens panel reviewing the county's desegregation efforts.

But the panel said that the school system should not open new magnet programs solely to meet the unrelenting demands of parents, most of them blacks, who have been unable to get their youngsters into the schools.

The Committee of 100, headed by Bowie State University President James Lyons, is expected to submit the results of its two-month study on the future of the county's desegregation plan to the Prince George's Board of Education next week.

In the next few months, the board is expected to use the report as a guide in making critical decisions affecting the magnet programs, the cornerstone of a court-ordered desegregration plan and the chief alternative to mass busing.

The Board of Education, which finds itself the focus of national attention as it continues the innovative desegregation effort it launched in 1985, faces an array of controversial decisions.

Perhaps the most controversial of them deals with the continuing demand from the black community for the magnet schools, which feature smaller classes, state-of-the-art equipment and highly specialized courses. But the racially mixed Committee of 100 generally agreed that the county, already facing spending limits, should not create magnets not directly aimed at reaching the county's desegregation goals.

By design, the magnet system gives preference to white applicants to magnet schools, which are located generally in predominantly black neighborhoods.

Children who regularly attend those schools usually participate in the special magnet classes, and black children account for 58 percent of all magnet students. However, black youngsters not living in the regular attendance area of magnet schools are accepted only after neighborhood and nonblack children are enrolled.

"The general feeling . . . was that additional magnets should not be set up solely to address the black waiting lists," Lyons said this week.

Instead, the committee will recommend that the waiting lists be used for planning purposes, to help identify the most popular programs and the communities that want them, Lyons said. More magnets could still be opened, and as a result, he said, "We're saying it should be looked at."

The county has 11 magnet programs with 13,000 students at 41 schools. In modifying or expanding any programs, school officials must balance the numbers of black and nonblack children so that the majority of all schools in the county are no more than 80 percent black.

The panel's report will be a summary of the recommendations of four subcommittees, which met Thursday night. Among the recommendations are that the county extend a "continuous enrollment" policy to assure that students already in magnet programs can continue in similar ones. For example, seventh-grade math and science magnet programs will accommodate only half the number of students enrolled in similar sixth-grade programs this year.

Schools offering before- and after-school care -- Kettering, Apple Grove and Phyllis Williams Elementary schools -- should be dropped as magnets and replaced by more popular programs, such as the traditional academy schools in the county, according to the group's findings. Unlike others, the extended-day magnet has not attracted significant numbers of pupils who do not live in the immediate school areas.

One subcommittee had argued that magnet schools should be opened to accommodate the more than 2,000 students who are on the waiting list each year.

"If you have a program that so many blacks are trying to get into, and they can't get into them . . . I have to question the fairness," said Beverly Perry, a committee leader.

School board member Marcy Canavan, who represents the southeastern section of the county, said she believes the county should address the waiting lists. "It's clear . . . there's a lot of demand in my district," she said.

But the thrust of the panel's findings was to balance community wishes with the desegregation goals.

"The programs must not be expanded illogically and beyond the demonstrated capacity of the system to manage them," community activist Alvin Thornton wrote as part of the report.