Only 2 percent of husbands charged with killing their wives are acquitted, according to a Justice Department study that suggests the verdict in the O.J. Simpson case was unusual.

And the race of the accused or the victim does not appear to affect the verdicts or sentences, according to the just-completed study of spouse murder cases in the nation's 75 largest counties.Some experts said the results undermine the perception by some critics of Simpson's acquittal that black juries won't convict black defendants so the jury system should be altered.

"These large counties, which include Philadelphia, Chicago and New York, have large black populations with many black juries," said Patrick Langan, senior Justice statistician and co-author of the study. "Those black jurors are not tolerant of husbands murdering wives."

Asked about Simpson's acquittal on charges of murdering his ex-wife, Nicole Brown Simpson, and her friend, Ronald Goldman, Attorney General Janet Reno replied Thursday:

"When a jury returns a verdict, there are going to be some that are disappointed and others who are happy. And one jury verdict should not reflect on a whole system."

Eleanor Smeal of the Feminist Majority Foundation said the data indicate that race and gender are not undermining justice in spousal murder cases. "The difference in the Simpson case was the power of money," she said. "What normal person would have had the money for the best experts and enough lawyers to mount tens of thousands of objections?"

Another major finding of the study by the department's Bureau of Justice Statistics was that wives charged with killing their husbands were convicted less often than husbands facing spouse murder charges - largely because women successfully argued they were defending themselves from husbands who had abused them.

The Justice study sampled spouse murder cases concluded in 1988 and projected that 318 husbands and 222 wives had their cases wrapped up that year in the 75 counties, where more than half of all murders occur each year.

"This is the best and most comprehensive study ever done of spouse murder," said Marvin Wolfgang, University of Pennsylvania professor of criminology and law. Wolfgang, who got remarkably similar results in a smaller study of Philadelphia spouse murders during 1948-52, agreed with Langan that the 1988 data are still valid today.

Of the male defendants, 46 percent pleaded guilty, 41 percent were convicted at trial, 11 percent were not prosecuted and 2 percent were acquitted at trial. Of the guilty, 81 percent were sent to prison, for an average of 16.5 years.

Of the female defendants, 39 percent pleaded guilty, 31 percent were convicted at trial, 16 percent were not prosecuted and 14 percent were acquitted at trial. Of the guilty, 57 percent were sent to prison, for an average of 6 years.

Langan, the Justice statistician, said self-defense by women clearly accounted for their 70 percent conviction rate, compared to 87 percent for men. Of the female defendants, 44 percent had been threatened with a weapon or physically assaulted by their mate at or near the time of the killing, compared with only 10 percent of the male defendants.

"In cases where there was no provocation, husbands and wives had an identical conviction rate," Langan said.