Texas on Wednesday executed Lester Bower, one of the longest-serving inmates on the state's death row who had said he was wrongly convicted of killing four men in 1983 and had spent three decades trying to halt his capital punishment.

Bower was pronounced dead at 6:36 p.m. CDT after being given a lethal injection at the state's death chamber in Huntsville, a prisons official said.

A former chemical salesman with two children, Bower became the oldest death row inmate put to death in Texas since the U.S. Supreme Court reinstated the death penalty in 1976. The state has executed 526 people in the period, the most of any state.

A few hours before the execution, the U.S. Supreme Court rejected a last-minute appeal filed by lawyers for Bower, who had already faced imminent execution six times, according to court papers.

"Much has been written about this case, not all of it has been the truth. But the time is over and now it is time to move on. I want to thank my attorneys for all that they have done. They have afforded me the last quarter of a century," he was quoted as saying in a last statement by prisons officials.

Lawyers have made numerous appeals questioning his conviction with no incriminating fingerprints found at the crime scene, no murder weapon recovered and no witness to the crime.

He was found guilty of killing contractor Bob Tate, former police officer Ronald Mayes, sheriff's deputy Philip Good and interior designer Jerry Brown in a deal for a $4,000 ultra-light airplane that went bad.

Prosecutors said Bower killed Tate to steal the airplane Tate was selling and then killed the other three when they unexpectedly showed up at the hangar.

Investigators said they found parts from Tate's airplane at Bower's residence and that he had made calls to Tate. They said Bower, who also sold firearms, had acquired a gun and exotic ammunition similar to what was used in the killings.

In an interview published this week in the Fort Worth Star-Telegram, Bower, who had no criminal record prior to his arrest, said he did not commit the crimes and was wrongly convicted.

"What's more, I feel we have had a reasonable number of people come forward with credible stories to say I did not commit these murders," the newspaper quoted him as saying.