Yale and Stanford universities are abandoning the popular, but increasingly controversial, early decision system that requires applicants to promise that they will attend a college that accepts them ahead of the usual admissions schedule.

The schools announced their decisions separately yesterday, but the combined effect will put pressure on other colleges to do the same or risk losing in the competition for some of the best applicants, according to admissions experts.

Although Stanford and Yale are not the first colleges to drop early decision, they are the most selective to do so.

"I hope this will serve as a catalyst for other institutions to examine their policies and see if they are in the best interests of the students and the institutions," said Martin A. Wilder, a vice president of the National Association for College Admission Counseling.

Wilder also is vice president for enrollment at Mary Washington College in Fredericksburg, which along with Beloit College in Wisconsin and the University of North Carolina at Chapel Hill recently said they were eliminating early decision.

The programs -- in which applicants find out by mid-December whether they have been accepted, rejected or deferred until the usual spring decision day -- have grown in popularity as students try to shorten the suspense and improve their chances of getting into top schools.

Many high school counselors, as well as some parents and students, have complained that the process forces teenagers to decide too early and handicaps low-income families, who lose financial aid leverage when they commit early to one school.

Dave Hamilton, director of college counseling at Our Lady of Good Counsel High School in Wheaton, said of the Yale and Stanford announcements: "Applause and kudos. They will score points from students, parents and counselors everywhere."

In an interview yesterday, Yale President Richard C. Levin said he first sought a meeting of all Ivy League schools to discuss dropping early application programs but decided to go ahead on his own. He concluded that the eight Ivy League schools were unlikely to agree. He also was advised that such a meeting might be seen as illegal anti-competitive action.

"Early decision programs help colleges more than applicants," Levin said. He said he wanted to "restore a measure of reasoned choice to college admissions" and hoped that other colleges will follow suit.

Robin Mamlet, dean of admission and financial aid at Stanford, said her university wanted students "to feel free to apply early but have the flexibility to wait to commit." She said Stanford had not planned to announce the change yesterday but decided to go ahead when it heard Yale's announcement. She said the university knew it would be asked for comment "and we wanted to be clear about our intentions."

Both Yale and Stanford said they would adopt, for 2004 high school graduates, an "early action" system, in which applicants are notified by mid-December but are not bound to attend if accepted.

However, the universities said applicants will be told that they can apply only to that school -- not to any others -- for early action admission. This is a violation of a National Association for College Admission Counseling rule that says a student can apply to only one school early decision but to any number of early action schools.

"I don't understand how they can remain members [of the association] and flout the guidelines," said Sally O'Rourke, a counselor at Andover (Mass.) High School.

Levin said he did not believe the association had the legal power to enforce such a rule. An unrestricted early action system, he said, creates the possibility of every student applying to every college in November, a recipe for administrative chaos.

Some admissions experts said they thought Princeton and other selective colleges might be the most likely to follow Yale and Stanford's lead, as they often compete for the same students. Harvard does not have an early decision program, but offers an early action program with no restrictions.

Princeton spokeswoman Lauren Robinson Brown, however, said early decision "serves our students well and we have no plans to change it." Lee Stetson, dean of admissions at the University of Pennsylvania, said his school would keep its early decision program for the same reason. He said it has increased the number of students for whom Penn is their first choice, and "it has changed the tone of the campus."

Yale and Stanford plan to adopt "early action" systems, in which applicants are not bound to attend.