Sharp division on death-penalty cases. SUPREME COURT

Two United States Supreme Court rulings handed down yesterday on the death penalty indicate how sharply split the justices are over this issue. The high court narrowly decided, 5 to 4, to uphold a murder conviction and execution of an Oklahoma man who had been denied an automatic challenge of a juror. The juror said he would vote for the death penalty in any capital case where there was a conviction.

At the same time, the justices, by a 6-to-3 vote, approved Texas law procedures for administering the death penalty.

In this case, the court's majority rejected the claim of a death-row inmate who said his jury was not completely apprised of circumstances relevant to his case. The jury's option to weigh ``mitigating circumstances'' could have guided them to a verdict of life imprisonment, rather than execution.

Texas is one of 33 states - of the 37 that impose the death penalty - that provide for jury participation in capital sentencing. However, all the other states require specific instructions about mitigating evidence.

In recent years, the Supreme Court has invalidated dozens of individual death sentences on the grounds of improper court procedures or racial bias in the jury or sentencing processes.

But it has consistently refused to strike down the capital penalty on the broad constitutional grounds that it constitutes illegal ``cruel and unusual'' punishment.

Last term, the justices narrowly decided that even if racial bias was inherent in the system, this was not grounds for throwing out the death penalty, or declaring a national moratorium on state executions.

In the Oklahoma case, the defendant had argued that the judge should have excused on his own a juror who admitted that he believed in imposing the death penalty for any capital offense. The defendant's lawyer was forced to use one of his limited number of ``peremptory challenges'' (those which don't require any cause to be shown) to dismiss this juror.

Chief Justice William Rehnquist wrote for the court's majority that ``so long as a jury that sits is impartial, the fact that the defendant had to use a peremptory challenge to achieve that result does not mean'' his constitutional right to a fair trial was violated.

Associate Justice Thurgood Marshall said in dissent, however, that where a ``man's life is at stake ... we should not be playing games.

``In this case, everyone concedes that the trial judge could not arbitrarily take away one of the defendant's peremptory challenges. Yet that is in effect what happened here,'' he added.

Justice Rehnquist also quoted from a previous Supreme Court ruling that held that ``the Constitution entitled a defendant to a fair trial, not a perfect one.''

The justices heard this case twice - the second time was after Reagan appointee Anthony Kennedy joined the court.

Justice Kennedy joined the chief justice and fellow Associate Justices Sandra Day O'Connor, Antonin Scalia, and Byron White - the court's new conservative majority - in providing the pro-death penalty edge.

Associate Justices Harry Blackmun, William Brennan, and John Paul Stevens voted with Justice Marshall in dissent.