Theodore R. Newman Jr., the embattled chief judge of the D.C. Court of Appeals, defended himself for two hours before the D.C. Judicial Nominations Commission Wednesday, responding to allegations by four of his colleagues that he is too intemperate and too much of an embarrassment to head the city's highest court, according to knowledgeable sources.

Newman steadfastly refused yesterday to discuss his testimony publicly. But he is known to feel that those trying to block his reappointment have breached the canons of judicial privacy in an irreparable and unprecedented manner. Newman also believes they have cast personal and philosophical differences in terms of judicial competence in an effort to bolster their case. d

Newman's testimony concluded a seven-hour, closed-door session, and in some instances he responded point by point, sources said, to the accusations of his opponents -- four conservative judges whose influence has waned since Newman's selection in 1976 as chief of the state-level supreme court in the nation's capital.

Four other judges also appeared before the commission Wednesday night and at least one of them, John M. Ferrin, supported Newman, sources said. The other three - Julia Cooper Mack, Catherin B. Kelly and William C. Pryor -- have tended to vote with Newman but have stayed clear of the active battle over his reappointment.

The 46-year-old chief judge is also known to believe that the effort to block his reappointment is motivated by philosophical and racial differences -- he is black, and all four of his opponents are white. He also believes that some of the allegations made about him are either patently untrue or misdirected attacks on his efforts to improve court efficiency, according to numerous sources.

Over the weeks leading to the show-down that began with scathing testimony from the four judges on Tuesday, Newman privately told acquaintances that he does not feel obliged to share his statutory authority with the others, and that his actions are no different from those of his predecessors or other chief judges of more conservative belief.

He has consistently refused to publicly discuss the battle over his reappointment because to do so might bring charges that he is engaging in the same kind of mudslinging that he believes his opponents have launched.

"Newman is in a tough position," said one knowledgeable lawyer. "It looks like other judges on his court have leaked material on pending cases and confidential commission proceedings to the media, and neither he nor his judicial supporters are willing or able to respond in kind. He has to do the best he can to preserve the court and himself."

The battle over the chief judgeship has thrown open the usually secret proceedings of the unobtrusive but powerful court in an unprecedented fashion. It has stunned judges and lawyers throughout Washington and led others to wonder how the nine-judge panel will be able to function effectively after the commission makes its decision next week -- regardless of the outcome.

The controversy dominated discussion yesterday at a previously scheduled meeting of D.C. Superior Court judges, according to sources. Several judges expressed fear of irreparable damage to the court. "How can they ever put Humpty-Dumpty together again," one judge said later.

"No one is a winner in such a matter, and most significantly the court will be the greatest loser," one trial judge said yesterday. "I believe that in some ways it will destroy the court. But in the long run, it may strengthen it . . . They're all fighting for survival now . . . It's going to be a miserably functioning body. Everybody's going to be out protecting their own skins in the future."

The seven-member commission can reappoint Newman as chief judge or select one of his eight colleagues. It cannot, however, remove him from the bench. That authority rests with another similar independent panel, the D.C. Commission on Judicial Tenure and Disabilities.

The opposition to Newman has been led by Judge Frank Q. Nebeker, who has been joined by Stanley S. Harris, George R. Gallagher and John W. Kern III. Yesterday, a retired appeals court judge, Hubert B. Pair, told a reporter he hopes to testify against Newman before the commission reaches its decision. Pair is black. The four judges opposing Newman contend some blacks as well as whites do not want him reappointed.

"I think the future of the court system and the administration of justice in this city transcends the importance of Ted Newman or the four judges that oppose him, myself or anybody else," Pair said.

The four dissident judges have told the commission that they believe Newman's conduct on the bench has demonstrated that he is unfit to be chief judge. They contend that he unfairly monopolizes oral arguments before the court, that he storms out of meetings before they end, that he is involved in partisan political activities and does not consult with other judges before announcing decisions on court policy.

Newman is known to believe, acquaintances say, that his stewardship of the court -- a position that involves vast administrative powers but includes more prestige than actual influence -- is representative of a changing of the guard in city judicial circles akin to the transformation of city hall under home rule.

Newman was educated at Harvard Law School, reared in a deep South, segregated community where blacks felt they had to be twice as good to be equal, and supremely self-confident. He is the first black to head a court once dominated by white, usually conservative judges who owed their positions to the same kind of federal city powers that home rule proponents considered colonial.

Newman's supporters sense desperation in the opposition of the four judges. Already, they point out, three of the courts in the city are headed by blacks -- D.C. Superior Court Chief Judge H. Carl Moultrie, I, U.S. District Court Chief Judge William B. Bryant and Newman. And the fourth, the U.S. Court of Appeals here, could also be headed by a black within the next 18 months -- Judge Spottswood W. Robinson III.

Newman and many of his supporters feel that his actions would be less likely grounds for criticism if he were white, or if he were more conservative. The chief judge is known to feel that he has strong support among politicians, ministers and black and white members of the legal establishment in Washington.

In a number of court reports during his tenure, Newman has cited various administrative changes that he contends demonstrate the court procedures have improved since he took over. He initiated, for example, a procedure for settling complicated civil cases that avoided lengthy appeals proceedings and thereby relieved the appeals court of part of its heavy caseload.

Many courthouse observers also believe that Newman, an active participant in the National Center for State Courts, a judicial think-tank in Williamsburg, Va., has significantly bolstered the national prestige of the 10-year-old appeals court, often considered a stepchild to other, longer-established state supreme courts.

Newman has also pushed hard in local legal circles for the establishment of an intermediate court of appeals that he and others contend would improve court efficiency and reduce case backlogs. Some lawyers who frequently practice before the court also assert that the quality of opinions have improved since Newman took over.

"There's no one judge that stands out over there for the quality of his or her work," said one longtime observer of the court. The source said opinions written by Newman are "what they should be from the highest court of the state."

But, the source said, Newman's capabilities as a lawyer, which are well-respected on a scholarly level, are not relevant to the post because it is largely an administrative job. Newman's legal work, the source said, "is not what this controversy is about."