University of Massachusetts President William M. Bulger, one of the state's most powerful and charismatic public figures, today refused to answer questions under oath from a congressional committee investigating ties between rogue FBI agents in New England and their mob informants dating back to the 1960s -- informants including his brother, the fugitive gangster James "Whitey" Bulger.

"One of the Fifth Amendment's basic functions is to protect innocent men who might be ensnared by ambiguous circumstances," said Bulger, 68. "I find myself in such circumstances."

A former state senate president known for delivering feisty jabs in his Boston Irish lilt, Bulger invoked his constitutional right against self-incrimination less than 10 minutes into this morning's proceedings, leading the House Committee on Government Reform to adjourn abruptly.

The committee, chaired by Rep. Dan Burton (R-Ind.), opened its hearing here Thursday after spending nearly two years exploring a seedy era of dealmaking between New England FBI agents and organized-crime figures that resulted in murders, bribery, compromised criminal investigations and the imprisonment of innocent men. The revelations have led to civil lawsuits against the federal government by murder victims' relatives, among others, and the conviction earlier this year of a former FBI agent on charges related to his warning mobsters of impending indictments.

The panel sought to question Bulger about his brother, 73, a former top-echelon FBI informant who stands accused of racketeering, extortion and other offenses in connection with nearly two dozen murders but who has eluded authorities since 1995. The Boston Globe reported earlier this week that William Bulger last year told a grand jury that he had spoken to his brother shortly after Whitey Bulger left town in a departure propelled by a tip about an impending federal racketeering indictment by John J. Connolly Jr., the renegade FBI agent who was convicted earlier this year.

In excerpts of the grand jury testimony published in the Globe, Bulger acknowledged that he had received a phone call from his brother several weeks after Whitey became a fugitive. He said he didn't urge his brother to surrender "because I don't think it would be in his interest to do so."

"So just to be clear, you felt more loyalty to your brother than you did to the people of the Commonwealth of Massachusetts?" asked Assistant U.S. Attorney James Herbert.

"I never thought of it that way," replied Bulger, according to the report. "But I do have an honest loyalty to my brother, and I care about him. . . . It's my hope that I'm never helpful to anyone against him. . . . I don't have an obligation to help everyone to catch him."

On Thursday, Bulger and his attorney, Thomas R. Kiley, asked a federal judge to release the secret minutes and provide Bulger with an extension of the immunity from prosecution he was granted last year.

The requests were denied, and it remained unclear until the last minute whether Bulger, who had refused to testify before the panel, would honor its subpoena to appear today.

Kiley said he had strongly advised Bulger to invoke the Fifth Amendment out of concern that law enforcement agencies interested in "settling old grudges" might try to entrap him and that discrepancies in his testimony could lead to perjury charges.

Agreeing with a characterization of the investigation as a "witch hunt" after today's hearing, Kiley cited the case of another brother, John P. "Jackie" Bulger, who was charged with perjury and obstruction of justice for allegedly lying to a grand jury in 1998 about his contacts with Whitey.

"If they cannot have one Bulger, we fear they will have another," Kiley said.

Burton disagreed, saying he was disappointed that the committee could not get what it considers "essential" information from Bulger about Whitey and Connolly, a childhood friend of the Bulgers' from South Boston. Connolly was convicted earlier this year for warning mobsters about indictments, and a confessed hit man testified during his trial that William Bulger had asked the FBI agent to protect his brother.

Burton opened today's session with a quote from philosopher Edmund Burke -- "The only thing necessary for the triumph of evil is for good men to do nothing" -- and then rebuked Bulger for not being "more willing to discharge his civil responsibility."

"I understand Whitey Bulger is his brother, but he's one of the Ten Most Wanted fugitives in the United States," said Burton after the hearing adjourned. He compared Bulger's predicament to that of David Kaczynski, who helped lead authorities to his brother Ted. "I feel very strongly that he ought to go down the same road as the brother of the Unabomber did, and that is: Do what's right for the country."

Rep. Martin T. Meehan (D-Mass.), a member of the Government Reform Committee as well as the House Judiciary Committee, said he would support seeking immunity from prosecution for Bulger to get his testimony in open court. Immunity requires a two-thirds majority vote of the Government Reform Committee.

"It would be the prudent thing to do," Meehan said.

Some committee members and political observers said they understood Bulger's concerns about the leaked grand jury minutes, but they also speculated that his reputation could suffer from his decision not to cooperate with the panel.

But Grace Fey, head of the board of trustees at the University of Massachusetts, upheld his right to constitutional privilege as an innocent man. "We have enormous confidence in President Bulger," she told reporters.

During Thursday's hearing, Jeremiah T. O'Sullivan, former chief of the New England Organized Crime Strike Force, testified that he knew Whitey Bulger and another mobster, Stephen "the Rifleman" Flemmi, were both murderers and FBI informants, but that he did not indict them in a 1979 horse-race fixing case in which 21 other gangsters were charged because he felt he did not have enough evidence to convict them. Today, after quickly denying requests from Bulger that his testimony be postponed or closed to the public, Burton asked Bulger if he had spoken to his brother Whitey since 1995.

Bulger responded he would not answer the question and invoked his Fifth Amendment rights.

Burton then asked if he intended to answer all questions in the same manner.

"Yes, sir," Bulger said, and the hearing ended.

William M. Bulger, brother of mobster James "Whitey" Bulger, invoked his Fifth Amendment rights yesterday during testimony before the House Government Reform Committee.