JACKSON, Ga. (AP) _ William Boyd Tucker, convicted of killing a pregnant newlywed 10 years ago, was put to death Friday evening in Georgia's electric chair.

Tucker was pronounced dead at 7:29 p.m., said Fred Steeple, a spokesman for the Georgia Department of Corrections. He was the 75th person to be executed in the United States since the death penalty was restored in 1976.

Earlier Friday, the U.S. Supreme Court voted 6-3 to reject a formal appeal aimed at overturning Tucker's conviction and his death sentence.

Tucker, 31, was convicted of the 1977 murder of 19-year-old Kathleen Parry during a convenience store robbery in Columbus.

He seemed almost in high spirits as the guards escorted him to the chair and seated him.

As he was strapped into the electric chair, Tucker read a three-page final statement condemning the death penalty.

''I take full responsibility for my crime but I must speak out against capital punishment,'' he said. ''No matter how sterile and sanitary you make this execution, it's still murder.''

The final statement was held for Tucker to read by prison chaplain Nolan LaVell. Much of Tucker's final words were inaudible to witnesses because of microphone problems.

Justices William J. Brennan, Thurgood Marshall and Harry A. Blackmun voted to spare his life. Brennan, in an opinion for all three, said there was a question whether the judge's instructions to the jury at Tucker's trial unconstitutionally shifted the burden of proof to the defendant.

Justice Lewis F. Powell, acting only two hours before Tucker was to have been executed Thursday, had granted him a 24-hour stay of execution so the full court could study the appeal.

Tucker also had been scheduled to die Wednesday, but was granted a 24-hour stay by the 11th U.S. Circuit Court of Appeals to give his lawyers time to appeal to the Supreme Court.

''We're here to show that we went through ten years of grief,'' Leonard Knipe, one of the victims two brothers, said outside the prison. ''That's a lot of hurt. We just want it to be over.''

Since Wednesday, a large group of relatives, including Tucker's mother and stepfather, George and Nancy Horan, have been visiting with the condemned man in a holding cell near the death chamber at the Georgia Diagnostic and Classification Center near Jackson.

Mrs. Horan said Tucker has accepted his death sentence.

''In prison he was saved. He knows he is going to heaven and he wants everyone to be with him,'' she said.

The Georgia Board of Pardons and Paroles earlier denied Tucker's petition for clemency. Board Chairman Wayne Snow said the decision was based on the terror inflicted on Mrs. Parry during the Aug. 20, 1977, robbery and abduction.

Mrs. Parry had been married two months previously, and was one-month pregnant.