More than 39 percent of Prince George's County's high school students were declared ineligible yesterday to participate in extracurricular activities under a new county rule -- the first in the Washington area -- that requires athletes and club members to maintain at least a C average.

The percentage of ineligible students ranged from a high of 54.9 at Bladensburg High School to a low of about 30 at Eleanor Roosevelt High.

The overall percentage translated into 14,195 of the 36,197 students in grades 9 through 12 being barred from extracurricular activities, and the impact was swift and widespread. Laurel Junior High disbanded its boys' junior varsity basketball team yesterday afternoon after four players failed to make the cutoff. Roosevelt's boys' basketball team lost four of its top seven players and nine DuVal High wrestlers were put off that team.

Elsewhere in the county, cheerleaders, band members and student government officers were dropped from their clubs.

"Of course, I'm disappointed so many youngsters are ineligible," Superintendent John A. Murphy said after report cards were released yesterday. "For some, it will take longer for the rule to sink in. But the day has arrived, and now they have to pay the price."

Students generally supported the regulation, despite its impact.

But 16-year-old Mark Fowler, who was kicked off the Frederick Douglass High School wrestling team, was disappointed. "I think it's unfair because I've been practicing hard all season. There's only a month left. It's a lot of hard work down the drain," said Fowler, who got three Ds, two Cs and a B on his report card.

He said his father was planning to appeal the rule to the school board.

At Laurel High School, where more than 38 percent of the students did not attain a C average, Principal Thomas Kirby was unperturbed: "We're not devastated by this. I don't see any point in having a kid who can bounce a basketball graduate from high school and not be able to read."

The minimum grade average, which affects students in grades 9 through 12, was adopted by the Board of Education last spring in a move to raise academic standards.

Similar requirements have been approved in a few communities elsewhere in the country, including Alexandria, where the regulation takes effect next fall. In Springfield, Mass., a committee said last week it may soften its requirment that students get a C in all major subjects after members were deluged with complaints.

Yesterday, as first-semester report cards were distributed, students in school corridors caucused to assess the damage.

"Grades are the topic of conversation today," said Paul Lewis, principal at Forestville High School, where nearly 41 percent of the students didn't make the cutoff. "There's a buzz -- not necessarily a negative buzz, but a real buzz. Everybody's going around saying, 'Did you make it? Did you make it?' "

Lewis said four junior varsity basketball players are ineligible to play, in addition to one varsity player, four wrestlers and "a variety of student-government types."

While the impact of the rule may be most obvious on the basketball court and in other sports arenas, the fallout was delayed yesterday when all events scheduled were canceled because of the weather.

Percentages at most of the 20 high schools fell within a few points of the county-wide average. At a handful of schools, however, eligibility was still undetermined for as many as 13 percent of the students because of incomplete course work or late grades.

Official figures were not available showing how many individual teams and clubs lost membership.

While most reaction has been positive, some coaches and students expressed mixed feelings.

"Sports is another part of education," said Suitland basketball coach Irvin Hay. "Sports and athletics are the only reason some people come . . . . Everybody's just not good with books."

Sixteen-year-old Hope Butler said some of her friends think the rule is unfair. "They try their best, but just can't make it," said Butler, a junior at Gwynn Park High School and president of the county's student government association. "I can understand it from both ways. In Prince George's County, our grades have been poor for awhile. We need to get back to academics."

At Bladensburg, 869 students of 1,582 enrolled at the school were declared ineligible.

"We've got our work cut out for us," said Principal Ronald Cunningham. "I think we can do a lot better."

Other schools with high percentages of ineligible students were Suitland, with 47.3 percent, and Northwestern, with 47.2 percent.

DuVal High School, where 46.2 percent of the students are ineligible, lost 19 of its 63 athletes, according to athletic director Antoine Delity. Two of the students were key guards on the boys' varsity basketball team.

"Some of the students were surprised at the grades they got," Delity said. "They felt something would come along and the 2.0 C-average rule would be abolished. A few got caught."

Despite the high percentage of failures, Suitland's athletic teams did not suffer significantly, according to athletic director Ken Lima. He said two players on both the varsity and junior varsity boys' basketball teams were barred from playing, in addition to one boys' track team member and one pompon girl.

Before grades were issued, he said, "I was definitely concerned about it. But we've been going over and over it with the kids. Thank goodness, most of them slipped through."