Chancellor John B. Slaughter yesterday said he was considering a change in University of Maryland policy that would significantly toughen academic requirements for athletic eligibility. Athletic Director Dick Dull said last night he expected such a plan to be in place for the 1987-88 academic year.

The proposed policy, which Slaughter submitted to a task force studying the academic achievement of Maryland athletes, would require seniors to maintain a C average. The eligibility of underclassmen would be determined on a sliding scale, depending on number of credits attempted. After the freshman year, an athlete would need at least a 1.78 grade-point average on a 4.0 scale.

If this policy had been in effect last season, four of 12 active men's basketball players and three of 16 women's basketball players would have been declared ineligible at midseason, according to sources and university data compiled in February. Thirty of 126 football players, including walk-ons, would have been ineligible, according to the same data.

Of the 370 athletes on Maryland's other 19 teams, 42 would have been ineligible.

Currently, any athlete who is enrolled full-time at Maryland is eligible to compete.

"This policy may be controversial in that we are establishing higher standards for our student-athletes," Slaughter wrote in a letter distributed to a subcommittee studying academic support programs and policies. "However, I believe it is reasonable, educationally sound and long overdue."

Later, in a telephone interview, Slaughter said, "I sort of conceived the elements of an idea but thought I ought to explore it with someone who can look at it in greater depth than I'm able to."

Dull, who was out of town during the day, said he and Slaughter discussed the eligibility plan last week. "He asked me, 'Is there any doubt in your mind that this is the way we need to go?' And I said, 'No,' " Dull said.

"This is an initiative of Dr. Slaughter's, and my feeling is the people will always do the minimum. If the minimum to be eligible is to be a full-time student, that's what they'll be. If the standard is to be above academic warning, they'll gravitate to that standard. If they can't meet that standard , they don't belong in intercollegiate athletics anyway."

Dull said that Slaughter wanted to wait until the 1987-88 academic year because he wanted input from the task force and "it would be unfair to athletes as well as the institution" to implement such a radical change for the upcoming school year.

Associate athletic director Randy Hoffman said, "Obviously, if it was implemented tomorrow, it would have an effect on the department."

Slaughter said he had been thinking about such a policy since last fall.

The chancellor said it was likely Maryland would become the nation's first public university to institute such a standard. Most schools with big-time sports programs follow NCAA minimum guidelines for eligibility, which require an athlete to pass 24 credits in a degree program per year and to be in whatever the university considers "good academic standing."

Slaughter said that Notre Dame and perhaps a few other private universities have higher standards. An NCAA spokesman said no such data was available. At Notre Dame, after the first semester of the freshman year, an athlete must maintain a C average (2.0 on a 4.0 scale). Brian Boulac, an assistant athletic director, said the policy is the same for all extracurricular activities, not just athletics. The proposal at Maryland would apply only to athletes.

Slaughter said he has discussed his idea with Digger Phelps, Notre Dame's basketball coach. In a telephone interview, Phelps said only two players in 15 years have had problems with that rule.

"They don't fool around," he said. "In addition, I have my own rules. I find out you cut class, you don't play the next game. That's a Digger rule."

At North Carolina, basketball coach Dean Smith has a similar rule. Dull has said that unexcused absence from class is the biggest reason for academic failure of Maryland's athletes, and has proposed a mandatory class attendance rule for high-risk athletes.

"I believe firmly that we must establish a policy that encourages and supports the retention of student-athletes toward graduation and not merely eligibility. Our current practice . . . is not consistent with that philosophy," Slaughter wrote in his letter.

"Participation . . . is a privilege that a student earns. These individuals serve as representatives of the campus and, therefore, it is appropriate to establish higher academic performance requirements for participation in intercollegiate athletics."

Football coach Bobby Ross declined to discuss the issue. Basketball coach Lefty Driesell, who will be asked to appear before the task force, was unavailable.

Slaughter already has ordered management of the academic support unit for athletes moved from the athletic department to the academic sector. Phelps said academic advisers at Notre Dame are separate from the athletic department. Is that best? "Absolutely," he said. "They should be a liaison between the student and the faculty, not the coach. And when he the adviser calls, it's like E.F. Hutton. We all listen."

Azizuddin Abdur-Ra'oof, a good student, star receiver on the football team and member of the task force, said of Slaughter's eligibility proposal: "It's a move in the right direction. That way they won't achieve only on the field, but when they come out of school."

Bruce Mesner, a star defensive lineman, said: "I would support something like that. Everybody is capable of getting a 2.0."

Len Elmore, a task force member and former basketball star now attending Harvard Law School, said, "If you raise the eligibility standards higher than the NCAA's, there were times I wouldn't have been eligible. But it gives them incentive to do better."

After disclosing Slaughter's plan, subcommittee members voted to close their meeting to the public, as the other four subcommittees did as their first order of business. It was the first time in four weeks that the task force had closed any session.

Slaughter said he was frustrated by disclosures by university officials after subcommittee meetings last week and said he believes the subcommittees can get more candid input if sessions are closed. Task force chairman Robert Dorfman cited discussions of personnel and other sensitive matters as reasons for closing yesterday's meetings.

Lawyers for the Baltimore Sun challenged the closing in Prince George's County circuit court. But Judge Audrey Melbourne postponed a hearing until Friday. The subcommittees are not scheduled to meet again until Monday. Lawyers for The Washington Post, who were still considering their options, said they deferred action because the Sun already had gone to court.

Staff writer Sandra Bailey contributed to this report.