With less than six hours to go before his scheduled electrocution, John Louis Evans III, a loser in life who was willing to die for his crimes, was granted a dramatic stay of execution tonight by Supreme Court Justice William Rehnquist.

Rehnquist, saying he does not usually grant stays of exevution, said he was doing so in this case because death is irrevocable and he was acting on behalf of the entire court.

Evans' execution - a jolt of 2,400 volts to be delivered by a special prison generator - would have fulfilled his desire for a quick death rather than serving a life term in prison for murdering a pawnbroker.

As he had since the day in 1977 when he told a jury he would kill again if it did not order him executed, Evans remained steadfast throughout the day. But events were beyond his control.

Lawyers for the Southern Poverty Law Center, acting on behalf of his mother, Betty, had petitioned Rehnquist for a stay to keep Evans alive.

"If I were casting my vote on this application for a stay of execution as a member of the full court, I would vote to deny the stay," Rehnquist said in a seven-page opinion.

"Evans has been found quilty of an atrocious crime, sentenced oto be put to death in accordance with Alabama law, and has had his conviction and sentence reviewed both by the Alabama Court of Criminal Appeals and by the Supreme Court of Alabama."

Because of the irrevocability of the action, Rehnquist said he preferred to have the full court study the appeal by Evans' mother.

With twilight upon the Holman State Prison, where Evans had awaited death, Rehnquist blocked any execution before 5 p.m. April 13.

Rehnquist directed state officials to formally reply to the mother's application for a clemency hearing for her son. But he also directed Evans' lawyers to explain why they had waited until almost the eve of the execution to file court papers in Alabama to block it.

Evans was described as resting today in the condemned prisoner's cell on death row in the west wing of Holman, Alabama's maximum security prision.

The 42 other inmates on death row cheered when Rehnquist's order was announced, according to the Rev. Kevin Duignan, who spent most of the day with Evans. The priest said Evans had mixed emotions about the decision, and that he appeared "dismayed."

According to corrections spokesman John Hale, "John was crying and visibly very upset." Asked if he had anything to say, the normally voluble Evans said, "No comment," Asked if there was anything that could be done for him, an angry Evans said, "No, not now."

He was to die at 12:01 a.m. Friday, and was described earlier today as being "in control" and sincere in his preference for death.

His would have been the first execution in the United States since Jan. 17, 1977, when a Utah firing squad ended the life of Gary mark gilmore. Like Gilmore, Evans had wanted to die and had told his lawyer not to appeal.

But unlike Gilmore's case, where various legal groups went to the Supreme Court in a vain attempt to save him, this time the court spared, at least for the time being, Evans.

Members of various legal and anticapital punishment groups who have talked with Evans over the months expressed their belief at an afternoon press conference that if the execution were blocked, Evans would join in a full appeal of his sentence.

While Evans has stressed that his decision to die was, in part, a protest of prison conditions in Alabama-considered to be among the worst in the nation-he has emphasized that whatever the living conditions in Holman, he prefers death to incarceration.

"I choose to die because I want to be free," he said Wednesday. "I must have my physical freedom. It is an obsession with me."

So until dusk today, the day was like many others for 29-year-old John Evans-except that he lived it believing it was his last day of incarceration and there would be no tomorrows.

The sky was April azure with a brilliant sun. The reddish brown fields separating Hwy. 21 from the prison were greening up with corn and soybeans. The prison was all but hidden from the 200 reporters who gathered here to record what would have been the second execution in the United States since 1977.

Warden Joe Oliver said at a press conference earlier today that he had had "quite a few" volunteers to activate the switches for the electric chair.

Evans was convicted of the Jan. 7, 1977, robbery-murder of a Mobile, Ala., pawnbroker, Edward Nasser, whose death was witnessed by his two young daughters.

"I've been at it a long time, Evans said of his life of crime during an April 1977 address to his jury in Mobile. "And if you don't come back with a death penalty, I'm going to get out and I'm going to do it again . . . I have no intention whatsoever of ever reforming in any way, and I would rather die by electrocution than spend the rest of my life in a penitentiary."

While his priorities in life apparently remained in that order through today, others say Evans has changed, and now regrets the pain he caused.

"And family I have hurt," he said Wednesday, "and particularly the litle children who have suffered by what I have done," to them, I say, I am deeply, deeply sorry and hope that someday they will find it in their hearts to forgive me."

Evans had said he wanted young people to see in his execution the final prize of a life of crime. Since the age of 14, he said, "I have robbed and burglarized and stole and murdered and always was a few feet ahead of the law. Oh yes, I enjoyed it.

"It was fun while it lasted but look where it has brought me."

Where it brought John Evans was to Death Row with a death wish. CAPTION: Picture, John Evans pauses while reading a statement to reporters before stay. UPI