AMHERST, Mass. (AP) _ More than 2,500 University of Massachusetts students clasped hands to form a line stretching over a mile as a demonstration against racism Thursday, two years after a post-World Series racial clash on campus.

''I'm so proud. We did it,'' said Lori Edmonds, president of the Afrik-Am Society, with tears streaming down her cheeks as she ran along the line, mostly of white students, hugging friends.

Music Professor Horace Boyer played ''We Shall Overcome'' on the carillon as the students spread out from the campus pond. Some sang, but most of the students appeared not to know the words to the civil rights anthem that stirred earlier generations.

''So many things promote separatism and ethnicity on this campus and elsewhere that there comes a time when you need to look at the things we have in common,'' said Chancellor Joseph Duffey from the line.

''This is an excellent idea. We have to raise the awareness of people like the chancellor,'' said Anthony Walker, a black senior from Washington, D.C., raising Duffey's hand.

Jason Rabinowitz, a student government leader, said black and white students remain skeptical about the affirmative action commitment of the 26,000-student state university, which has a 2.5 percent black enrollment.

University officials have promised to increase that level and improve the racial climate on campus since 10 students were injured in fights between black New York Mets fans and white Boston Red Sox boosters following the Mets victory in the 1986 World Series.

In February, students took over a building called the New Africa House, leaving only after administrators agreed to several concessions.

''The programs for minority students they promised to increase have actually been cut,'' Rabinowitz told a noontime rally. ''The renovations they promised to New Africa House have not begun. And the numbers of black students enrolled has not changed.''

University Admissions Director Timm Rinehart said 368 minority group members enrolled in the freshman class this fall, one more than had enrolled in the fall of 1987. But while enrollments of Asians increased 20 percent, the number of black freshmen was down 10 percent to 124.

Rinehart said the university had a 40 percent increase in minority student applications and a 25 percent increase in black student applications, but lost many prospective black students to competing colleges and universities.

He said the university recently tabulated a survey of black students who were accepted but decided not to enroll. A quarter said the negative racial climate on campus was at least somewhat of a factor, Rinehart said.