McALESTER, Okla. (AP) _ A woman convicted of killing her son's ex-girlfriend in 1982 was executed Tuesday night by lethal injection, making her the third woman and 17th inmate put to death this year in Oklahoma.

With the execution of Lois Nadean Smith, 61, Oklahoma now leads the nation in the number of executions this year.

Texas has had 16 executions, with one more scheduled before year's end. Oklahoma also has one more execution set for this year. Sahib Al-Mosawi, an Iraqi national, was scheduled to die Thursday for the killing of his wife and her uncle.

Smith is the last woman on Oklahoma's death row. No state has executed as many women in one year since the death penalty was reinstated in 1976, according to the Death Penalty Information Center in Washington.

Before the drugs were administered, she thanked her attorneys and asked for forgiveness.

``To the families, I want to say I'm sorry for the pain and loss I've caused you,'' Smith said. ``I ask that you forgive me. You must forgive to be forgiven.''

Smith was convicted of killing 21-year-old Cindy Baillie in July 1982. Baillie was shot nine times and stabbed in the throat.

Authorities said Smith and her son, Greg, picked up Baillie the morning of the killing. Smith then confronted her about rumors that she had threatened to have her son killed.

Prosecutors said Lois Smith began to choke Baillie and stabbed her in the throat with a knife; Baillie was then driven to a home where Lois Smith shot her.

Greg Smith was convicted of murder and given a life sentence. Prosecutors said he reloaded his mother's gun during the shooting.

Lois Smith's attorneys said she was trying to protect her son and was under the influence of alcohol and drugs at the time.