Gary Thomas Rowe Jr., the FBI's top informer inside the Ku Klux Klan in the 1960s, was indicted yesterday for the 1965 nightrider killing of civil rights worker Viola Liuzzo.

The sealed indictment was returned by a grand jury in Lowndes County, Ala., where the killing occurred.

County District Attorney Jesse O. (Jobie) Bryan yesterday confirmed that an indictment had been returned but he said he was forbidden by state law to reveal the name of any indicted person until that person has been served with a warrant.

Bryan said last month that he would seek a first-degree murder indictment against the former informer.

Rowe said in a telephone interview yesterday that he was told by his attorney, J. Paul Lowery of Montgomery, that he had been indicted and would soon be arrested. "My attorney had told me that they voted to indict me," he said.

The grand jury's action reopens one of the most bizarre criminal cases to spring from the 1960s civil rights movement.

It sets the stage for a possible trial filled with irony. It would feature defendant Rowe, the star prosecution witness in the 1965 Liuzzo murder trials: two former Klan members convicted on federal conspiracy charges stemming from the original case, who would be expected to become major prosecution witnesses against Rowe; and blacks, who were largely excluded from the original trials but who would play an important role in deciding Rowe's fate at a trial.

Liuzzo, a 38-year-old white civil rights worker from Detroit, was shot to death March 25, 1965, at the end of a high-speed car chase.

She had gone south to participate in the final, week-long stretch of a 50-mile voting rights march from Selma to Montgomery led by the late Rev. Martin Luther King Jr. After driving some marchers to Selma, she was returning to Montgomery along U.S. 80 when her car was overtaken by another filled with Klansmen, one of whom allegedly fired the fatal shot.

In two state murder trials, Rowe accused then-Klansman Collie Leroy Walkins of killing Liuzzo. He also testified against Eugene Thomas and William Orville Eaton, who were riding in the chase car with Rowe and Wilkins.

The two state trials ended with no convictions. Rowe, who was never charged, also testified against Thomas, Wilkins and Eaton in a federal conspiracy trial in which they were accused of violating Liuzzo's civil rights. All three were convicted and sentenced to 10 years. Eaton died before his appeal could be heard; Thomas and Wilkins served six years in jail.

In a segment aired July 10 on the BC News program "20/20," Thomas and Wilkins accused Rowe of murdering Liuzzo.

Thomas told The Washington Post that he had no intention of becoming reinvolved in the case after he finished probation.

"But people from ABC News started contacting us way back in 1977.They just kept us for a story until we said okay," he said, speaking for himself and Wilkins. He said neither of them received any money for the interviews.

Thomas said he and his accused colleagues did not speak against Rowe at the trials because their attorney, the late Matt Murphy, advised them not to take the witness stand or do anything that would place them in the car with Rowe.

"If we had told them we were in the car when Rowe shot that woman, we would've stood a chance of a first-degree murder charge. We kept silent and were tried on a lesser charge," he said.

District Attorney Bryan said he sought a first-degree murder indictment against Rowe because of the Thomas-Wilkins allegations. Both men appeared before the grand jury and are expected to testify against Rowe in a trial.

Rowe called the indictment a bum rap. He said the whole thing came about because of his book, "My Undercover Years With the Ku Klux Klan," accusing Birmingham police of instigating and participating in civil rights violence. He said Bryan "is a good buddy" with the Birmingham police, and that they would like to put an end to the book and an NBC movie based on it.

Birmingham police officials have denied the charges, which Rowe made again yesterday.

Bryan told The Post that he has "many friends" in the Birmingham Police Department and that he had received much help from the department in investigating Rowe, who he called a "confentital liar."