Harvard undergraduates would compete for a limited number of A grades in their courses under a faculty committee proposal released Friday meant to tame grade inflation at the Ivy League school.

During the last school year, about two-thirds of all undergraduate letter grades were A’s. Under the new proposal, grades of A would be limited to 20 percent of grades in a course, with an allowance of four additional A’s.

So, for example, a professor teaching a class of 100 students would be able to award up to 24 grades of A under the proposal, which could come to a vote by faculty this spring. There would be no limits on A-minus and lower grades.

Grades of A at Harvard are supposed to be reserved for work of “extraordinary distinction,” but they have exploded to become the majority of grades awarded.

In developing the proposal, the committee decided to propose returning the A to a lofty designation, as it had originally been intended, said Alisha Holland, a professor in the Department of Government at Harvard and a member of the committee that issued the proposal. “We thought, ‘What if we try to give meaning to the shared standards we already have around grading?’”

Joshua Silverstein, a professor of law at the University of Arkansas at Little Rock, said the proposal, if approved, should effectively control inflation and make grades more meaningful.