By Steve Olafson

OKLAHOMA CITY (Reuters) - A Tulsa County man convicted of killing his wife to collect nearly $1 million in insurance benefits was scheduled to be executed by lethal injection on Thursday at the state prison in McAlester, Oklahoma.

Barring a last-minute stay, Timothy Shaun Stemple, 46, will be executed around 6 p.m. local time and become the second man executed in Oklahoma this year and the 98th person since capital punishment was resumed in 1977, the Oklahoma Department of Corrections said.

He would be the ninth prisoner executed in the United States in 2012, according to the Death Penalty Information Center.

Stemple was a married kids' soccer coach in 1996 when he had an extramarital affair and enlisted his girlfriend's 16-year-old cousin to help him kill his wife of 11 years, according to evidence presented at his 1997 trial.

Trisha Stemple, 30, was beaten with a baseball bat, run over with a pickup truck and left on the side of a road beside her car, whose tire was punctured with a drill to make the crime appear to be random carjacking, testimony showed.

Timothy Stemple, who maintains he is innocent, might have collected on a $950,000 life insurance policy, but his teen-age accomplice testified against him in exchange for a life prison term, court testimony showed.

Stemple asked that his last meal be pizza, prison spokesman Jerry Massie said.

(Editing by Daniel Trotta)