The president of the American Federation of Teachers yesterday called for a federal scholarship program, offering a free college education in return for five years in the classroom, to attract top-quality students into teaching.

Union president Albert Shanker told a National Press Club luncheon that the scholarships were needed to counteract a drop in the academic ability of young people going into teaching. High achieving women, in particular, have recently surged into business and higher-paying professional fields, he said.

"If we can't find a sufficient number of talented teachers," Shanker declared, "none of the other education reforms are going to mean anything."

Under his proposal, Shanker said, the scholarships would be available only to students scoring in the top 25 percent on the Scholastic Aptitude Test (SAT) or some other nationwide exam.

Last spring the National Commission on Excellence in Education, whose report decried the "rising tide of mediocrity" in American schools, proposed giving incentives, such as grants and loans, to attract outstanding students to teaching. But the panel did not spell out how this idea might work.

Shanker, whose union claims 600,000 members, said the starting salaries of teachers should be raised substantially from the current average of about $12,000 a year to make education competitive with other professional fields. Even if this were done, he said, a scholarship program would be needed because top students "still would be offered more money" by private industry.

The union president said his proposal would cost about $7,000 per student yearly, and that those who didn't teach for the full period promised would be required to refund the money to the government.