The Justice Department yesterday promised an "expedited" inquiry into charges that a paid FBI informant was responsible for Ku Klux Klan killings of civil rights workers in Alabama in the 1960s.

Deputy Attorney General Benjamin Civiletti directed Philip Heymann, head of the department's Criminal Division and Michael Shaheen, who runs the internal watchdog unit, to review a series of recent charges about the informant, Gary Thomas Rowe.

News accounts this week have depicted Rowe, the FBI's chief informant in the Klan from 1960 to 1966, as an agent provocateur who shot civil rights demonstrators and might have been involved in the bombing of a black church in Birmingham in which four young girls died.

One report, from ABC News, suggested that Rowe fired the shot that killed freedom marcher Viola Liuzzo on a road outside Salem in 1965. The Justice Department, relying largely on information Rowe provided, successfully prosecuted three Klansmen for the Liuzzo killing.

Another report, in the Birmingham Post-Herald and The New York Times, said Rowe shot a black man to death in Birmingham in 1963 and was told by his FBI supervisor to keep quiet about it.

The FBI said Tuesday it has "no information to indicate that Rowe was involved in the crimes."

Yesterday morning, at a Senate subcommittee hearing on the FBI's use of informats, Edward M. Kennedy (D-Mass.) expressed concern about the Rowe matter and warned Heymann, who was in the witness chair, that the FBI should not be entrusted to investigate the charges by itself.

"There's a question of appearance," Kennedy said. "If this is a case of the FBI investigating itself, I'm not sure whether the American public is going to believe whatever comes out of the investigation."

Heymann, a law professor who was appointed to the Criminal Division post just last month, said he knew nothing about the Rowe case. He said the FBI had been in contact with Justice's Civil Rights Division on the issue.

A few hours later, however, Heymann was called to Civiletti's office and told that his division not the Civil Rights Division , would be in charge of finding out what Rowe had done during his years on the FBI PAYROLL.

Civiletti directed Shaheen separately to look into charges that FBI agents supervising Rowe blined at criminal activities of his.

Civiletti also asked for a review of the testimony at the Liuzzo shooting trial to determine whether that prosecution was based on false information.

The department set no target date for completing the investigations, but promised that they would be expedited.

Justice's first task will be review investigative files from the Birmingham police and the Alabama attorney general, both of which have been probing Rowe's activities.

These investigators became suspicious about Rowe's role in the Klan's bloody war against Alabama integration when Rowe gave "deceptive" answers on lie detector tests last fall about his part in the 1963 church bombing.

That suspicion led to further probes by Alabama officials, and separate investigations by news organizations. The probes became public in a serie of news reports this week.

At yesterday's hearing, Edwin J Sharp of the FBI's organized crime section said the number of informat has dropped from 11,000 in 1976 to about 2,800.

The cut w as due partly to a general tightening on the use of informants set in motion by former attorney general Edward Levi, Sharp said.

Another factor has been the Freedom of Information Act. Because organized crime figures can obtain their own FBI files under the act, Sharp said, informants became reluctant to provide information, for fear they might be identified indirectly in the files.