Three Northern Virginia teen-agers have alleged that the manager of a Manassas roller skating rink routinely banned young blacks and whites who skated together, threatened and intimidated blacks and their white friends and once fired a gun at two teens, one black and one white, according to a complaint filed in U.S. District Court in Alexandria.

The complaint says that the manager tried to discourage black and white teen-agers who were friends from coming to the rink by "prominently displaying, at the rink, a large wooden mallet inscribed by the clearly visible label 'Gary's Little Nigger Beater.' "

The suit was filed against Gary L. Quintin of Springfield, manager of the rink, Roll on America, and president of the company that owns it, by Alexandria civil rights lawyer Victor M. Glasberg. He has requested in papers filed with the court that a federal judge order that the alleged mallet be preserved as "extremely significant evidence" in the case.

Quintin described the charges in a recent interview as "a big crock of nothing." He denied each of the complaint's allegations. Asked about the mallet, Quintin replied, "No such thing."

"It sounds like a lot of hogwash to me," said Quintin's lawyer, Robert Willoughby of Manassas. "I've seen blacks and whites skating together there many times. Quintin can't stop that, you know that. It's just trumped up. An absolute denial is in order."

Chan Kendrick, director of the American Civil Liberties Union in Virginia, said the organization has decided to enter the case, and said he believes it is a "good example of modern-day racism in Virginia."

The rink, located at 8709 Mathis Ave. in Manassas, was acquired about six months ago by Southeastern Recreation Systems Corp., according to court papers. Quintin is identified in the suit as president of the firm.

According to the complaint, Quintin shot at two of the plaintiffs, Terri Harrington and James M. Thomas, after ejecting them from the rink last May, allegedly for skating together. Harrington, a 14-year-old Fairfax County resident, is white. Thomas, 19, who lives in Manassas, is black.

Quintin, arrested by Manassas police and charged with attempted murder of Thomas, pleaded guilty last month to a reduced charge of disorderly conduct and received a suspended six-month sentence, according to the complaint and court records.

Assistant Prince William prosecutor John Notarianni, who handled the case, said he plea-bargained with Quintin because Thomas was unavailable to testify and because a police officer who interviewed witnesses at the rink said he had gotten "two or three conflicting stories."

The complaint filed last Friday asserted Quintin banned blacks and whites who skated together by means of no-trespass notices issued to those who violated the rink's alleged racial policy. Quintin has denied the allegation.

Included in court papers were trespass notices allegedly signed by Quintin, given to Harrington and Thomas, and dated May 8, the day after Quintin was charged in the shooting incident.

The suit, which seeks to represent as a class action any patron subjected to Quintin's alleged racial policy, asks $50,000 in damages each for Harrington and Thomas and $3 million in punitive damages. It also asks that the court ban such alleged practices in the future.