In a major defeat for O.J. Simpson's defense, Judge Lance A. Ito ruled today that defense lawyers may present to the predominantly black jury only two of 41 tape-recorded excerpts in which detective Mark Fuhrman uses a racial epithet for blacks.

The judge barred the defense from submitting to jurors any statements Fuhrman made in nine years of taped interviews with a North Carolina screenwriter in which he boasted about planting evidence, beating black suspects, falsifying police reports and contriving probable cause to make arrests.

Lead defense attorney Johnnie L. Cochran Jr. angrily blasted Ito's ruling as "perhaps one of the cruelest, unfair decisions ever rendered in a criminal court in this country." Cochran said a decision had not been made on an appeal.

Simpson's lawyers had counted on dramatically completing their case this week or early next week by playing to the jury an hour-long audiotape montage of Fuhrman's incendiary statements, accompanied by text projected on a screen, in an effort to impeach his sworn testimony in March that he had not used the racial slur "nigger" in the past 10 years.

Instead, the defense will be allowed to play back only one short sentence that will take only a few seconds to hear and be permitted to show the jury the transcript of another brief sentence that was once on tape but was recorded over by screenwriter Laura Hart McKinny.

The defense had said that Fuhrman's boasts about planting evidence and contriving probable cause to arrest black suspects would be pivotal in their effort to win an acquittal.

The purpose was to demonstrate that Fuhrman, by his own admitted official misconduct, had shown he was capable of planting the bloody glove he said he found behind Simpson's estate the morning after the celebrity defendant's ex-wife, Nicole Brown Simpson, and her friend, Ronald L. Goldman, were brutally slain.

Ito, in a 10-page written ruling handed down this evening, said no credible evidence had been presented to suggest that Fuhrman planted the glove or any other evidence.

"This assertion is not supported by the record. The underlying assumption requires a leap in both law and logic that is too broad to be made based upon the evidence before the jury. It is a theory without factual support," Ito ruled.

He also said that Fuhrman's statements about police misconduct were so inflammatory that their probative value would be "overwhelmingly outweighed by the danger of undue prejudice."

The judge in many instances justified his decision on the grounds that Fuhrman's statements were irrelevant, would be a waste of time or were so inflammatory that the jurors could become blinded by emotion.

Ito said, however, that the defense can present to the jury two short statements Fuhrman made to McKinny in which he used the epithet "nigger." In one, Fuhrman said: "We have no niggers where I grew up." In the other, when asked by McKinny why black Muslims live in a certain area, Fuhrman replied: "That's where niggers live."

Ito also ruled that when McKinny is called to the witness stand, she can tell the jury that Fuhrman used the word "nigger" in a disparaging manner 41 times during his interviews for a fictional screenplay she wrote about the Los Angeles Police Department.

In explaining why he decided to allow the jury to hear any references to the racial epithet, Ito said the panel should hear evidence that relates to Fuhrman's credibility as a witness. "Just as a defendant with prior felony convictions testifying before a jury is not entitled to a false aura of credibility, neither is Fuhrman," the judge ruled.

Fuhrman has claimed through a spokesman that he exaggerated his comments to McKinny to make a better story for her screenplay and that he suffered a "mental block" when he testified he had not used the epithet for 10 years. His lawyer said he may invoke his Fifth Amendment protection against self-incrimination if he is recalled to the witness stand.

The judge's ruling on the admissibility of the two instances of racial slurs appeared to have at least satisfied the defense lawyers' need to demonstrate to the jury that Fuhrman lied when he testified about not using the term "nigger" and, therefore, should not be believed in any other testimony. Under California law, Ito is required to instruct the jury that if a witness is found to have lied about one aspect of his testimony, the jury may disregard the rest.

However, Simpson's defense team had said that a favorable ruling on the admissibility of Fuhrman's admissions of official misconduct would be even more important to winning an acquittal for their client.

Los Angeles District Attorney Gil Garcetti issued a written statement commending Ito's decision.

"While we deplore racism, these tapes are for another forum, another time, and not this murder trial," he said. "The court's ruling today will help keep the focus where it should be, which is on relevant evidence that allows the jury to determine whether Mr. Simpson is responsible for the murders of Ron Goldman and Nicole Brown Simpson. Now let's get on with the trial and get it to the jury."

Earlier today, Robert Tourtelot, Fuhrman's civil attorney, said he no longer will represent the retired detective because he was "profoundly disgusted and horrified" at Fuhrman's statements. But Tourtelot said he still is convinced that Fuhrman did not plant evidence at Simpson's estate and that he believes there is more than enough evidence to convict the former football star.

One of Tourtelot's associates, Hollywood private investigator Anthony Pellicano, said he was still working for Fuhrman and would advise the former detective to testify if he is recalled by the defense.

"My advice to Mark Fuhrman is to get on the stand and tell the truth, even though he's going to get criticized and lambasted," Pellicano said. "At least he can walk away from the stand with dignity."

Fuhrman, who is now being represented by attorney Darryl Mounger, returned to Los Angeles from his new home in Sandpoint, Idaho, Tuesday night to be here in case he is recalled to the witness stand.

Meanwhile, Justice Department officials said today that in response to a complaint by the NAACP they are looking into possible civil rights violations described by Fuhrman in the taped interviews.

Department spokesman Carl Stern said the NAACP complaint had been forwarded to the Civil Rights Division because "obviously, any time such allegations of police abuses of people's civil rights are made, they are within the purview of the Civil Rights Division and we would review them for possible further investigation and action."

In a letter to Attorney General Janet Reno, the Los Angeles branch of the NAACP cited Fuhrman's boasts of having beaten and "basically tortured" four suspects in the 1978 shooting of two policemen at a housing project, his claims of having tampered with evidence in criminal cases, his admitted fabrication of probable cause to make arrests and his singling out blacks for arrest without probable cause.

The American Civil Liberties Union of Los Angeles filed a friend-of-the-court brief asking Ito for access to all of Fuhrman's tape-recorded interviews with McKinny and to transcripts of tapes she has said were destroyed inadvertently. Special correspondent Kathryn Wexler contributed to this report. CAPTION: Judge Ito, below, said jurors can hear only two instances of Mark Fuhrman using racial epithet.