Howard Brooks, of Punxsutawney, Pa., a 24-year-old amateur boxer who collapsed in the ring after taking a left hook to the chin in a bout in Miami 10 days ago, died late Friday night, Miami General Hospital officials said. Brooks had been in a coma since the bout.

He was injured during a super-heavyweight match against Hank Williams of Fort Lauderdale in the South Florida Golden Gloves tournament at Victory Park Auditorium.

It was reported that a previously undetected medical problem may have been to blame for the death.

"The doctors told me they could see blood on the brain where there was a tiny bust of a blood vessel," said trainer Norman Wilson, who was working in Brooks' corner during the bout. "But they told me it looked as though something was already there. He barely got tapped . . . it was like a touch."

Brooks was a 1983 chemical engineering graduate of the University of Virginia . . .

In Colorado Springs, the U.S. Olympic Committee branded the American Medical Association's aggressive campaign against boxing a "disservice to a proud sport which has a proven track record of safety."

USOC President John B. Kelly, before his sudden death yesterday, said the AMA failed to consider "obvious and clear" differences between professional boxing and the carefully regulated, safety-conscious aspects of Olympic-style boxing.