In the first substantive move at compromise since the NCAA convention passed controversial Proposition 48 in January, the American Council on Education's Division I athletics committee proposed yesterday a modification that would benefit significantly the division's 17 historically black schools.

Meeting with representatives of the National Association for Equal Opportunity in Higher Education in Keystone, Colo., the ACE committee suggested an option that would retain the minimum standards of Proposition 48 in determining first-year athletic eligiblity but also allows freshman eligibility for athletes whose grades and test scores rank above the 10th percentile of his chosen school's most recent graduating class.

More research is scheduled and another meeting was set for Oct. 7 in Washington.

In effect, the ACE committee that pushed for passage of Proposition 48 has begun to fine tune the new rule, thus reducing its flaws and negative impact on black athletes. Proposition 48, due to go into effect in 1986, calls for a 2.0 average in a core curiculum of 11 academic subjects and a minimum score of either 700 on the SAT or 15 on the ACT entrance exams.

Presidents Joe Johnson of Grambling State and Jesse Stone Jr. of Southern, the two association representatives not on the ACE committee, were returning home and unavailable for comment. It was the first meeting between members of the ACE committee and the black educators since the day of the floor fight in San Diego at the NCAA convention that appeared to polarize the two sides.

It was unclear yesterday whether the association representatives would accept any proposal that used standardized test scores.

The association, preparing for a possible court case to strike down Proposition 48, said in a position paper that test scores should be used to "diagnose and develop, not to delete and destroy." In this light, Robert Klitgaard, a Harvard University professor, suggested using a combination of test scores and high school grade-point average to determine an athlete's academic risk at his chosen school.

Klitgaard came up with the 10th percentile proposal, according to a briefing book prepared for ACE committee members. "Rule 48 disqualifies student-athletes who are actually above average academically at some institutions," he said. "At the same time, at other institutions Rule 48 declares eligible some student-athletes who are at great academic risk."

According to Klitgaard, a student at a school where the average SAT score is 1,000-1,100 who has a 2.0 high school grade average and 700 on the SATs, will land in the lowest 7 percent of his class and projects a 1.78 college grade-point average. However, the same student at a school where the average SAT is 600-700, would be in the 50th percentile of his class and projects a college grade-point average of 2.16.

He noted that, according to 1981 SAT scores, 58 percent of blacks would not qualify under Proposition 48, compared to 14 percent of whites. But he noted that under the current NCAA rule of a 2.0 high school average in all courses, 8 percent blacks did not qualify, compared to 3 percent whites.

The ACE committee yesterday said it intends to toughen even further Rule 56, concerning progress toward a degree, and to specify that courses used in determining the core average in Proposition 48 must be college preparatory in nature.