A congressional committee charged with investigating ties between rogue FBI agents and mob informants voted today to grant immunity from prosecution to University of Massachusetts President William M. Bulger in hopes that he will provide testimony about his fugitive mobster brother, James "Whitey" Bulger.

With the endorsement of the Justice Department, the House Government Reform Committee also will be seeking information about law enforcement efforts to apprehend Whitey Bulger. Bulger, 73, has eluded authorities since 1995 when he learned about his imminent indictment on criminal charges in connection with nearly two dozen homicides.

William Bulger, 69, a former state Senate president, previously appeared before a grand jury but refused to answer questions under oath about his brother at a congressional committee hearing here in December, prompting widespread public criticism. He invoked his constitutional right against self-incrimination, saying one of the Fifth Amendment's basic functions is "to protect innocent men who might be ensnared by ambiguous circumstances."

Rep. Christopher Shays (R-Conn.) said, "This immunity will take away Billy Bulger's last excuse to not tell the committee what he knows about his brother's activities with the FBI." Shays is vice chairman of the House committee, which voted 30 to 1 to grant the immunity.

Bulger's testimony also could help shed light on a decades-long era of illicit relationships between New England FBI agents and their mob informants that resulted in killings, bribery, compromised criminal investigations and the imprisonment of innocent men. One FBI agent has been sent to prison for helping mobsters.

The committee also voted 34 to 0 to grant immunity from prosecution for Boston mob boss Francis Salemme, who entered a federal witness protection program after a judge ordered his early release from prison. A hearing date for the men to provide testimony has not been scheduled.

"This information will help the committee gain a complete understanding of the scope of the FBI's misuse of informants in Boston," said Rep. Thomas M. Davis III (R-Va.), committee chairman.

Bulger did not attend today's session. But he told reporters gathered at the state House here that the outcome was expected.

"It's another step along the way," he said. "Things have been going along in a pretty cooperative fashion, and so we'll do whatever is expected of us next."

Asked what he would tell the committee, Bulger replied: "I have no idea what they'll be asking."

Rep. Steven C. LaTourette (R-Ohio) cast the sole dissenting vote, saying Bulger should not be immune from prosecution if he knew about or was involved in any criminal activity or attempts to thwart criminal investigations in order to protect his brother. The Boston Globe reported that William Bulger told a grand jury that he had spoken to his brother shortly after Whitey fled town and did not urge his brother to surrender because "I don't think it would be in his interest to do so."

James "Whitey" Bulger on the FBI's Ten Most Wanted list in November 2000.

WILLIAM M. BULGER