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By Steve and Olafson

OKLAHOMA CITY, March 15 (Reuters) - An Oklahoma man was executed on Thursday by lethal injection for murdering his wife, who prosecutors say was beaten with a baseball bat and repeatedly run over with a pickup truck, to collect nearly $1 million in insurance benefits.

Timothy Shaun Stemple died at 6:11 p.m. local time, prison spokesman Jerry Massie said.

Stemple, 47, requested pizza and an orange soda for his last meal but did not offer a final statement, Massie said.

Stemple killed his wife Tricia in 1996. His plan to cash in on her death unraveled quickly at his trial the following year, when the 16-year-old nephew of his girlfriend testified he was promised a share of the insurance benefits to help in the killing.

The teenager was spared a possible death penalty in exchange for testifying for the prosecution and is serving a life prison term.

Tricia Stemple's body was found by the side of a highway in Tulsa County the day after her husband reported her missing. She died from blunt force head trauma and had fractures to her arm, ribs, pelvis, vertebrae and skull.

The 30-year-old woman's car was parked near her body with its hood raised to make it appear she had been attacked after her vehicle was disabled by a flat tire, but trial evidence revealed the tire had been deliberately punctured with a drill.

Stemple is 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 is the ninth prisoner executed in the United States in 2012, according to the Death Penalty Information Center.

Two more execution dates have been set in Oklahoma in April and May. (Editing By Cynthia Johnston and Tim Gaynor)