MANASSAS, Va. (AP) _ The woman who plans an insanity defense at her trial for cutting off her husband's penis agreed Friday to undergo psychiatric evaluation, a prosecutor said.

Lorena Bobbitt said her husband forced sex on her, prompting her attack. John Bobbitt was acquitted of sexual assault Wednesday.

Mrs. Bobbitt agreed to see a doctor from a state mental hospital before her scheduled Nov. 29 trial, said Mary Grace O'Brien, an assistant prosecutor in Prince William County.

''She is pleading insanity, so the state requests psychiatric information be provided to us to defend against the defense,'' Ms. O'Brien said.

The psychiatric exam could delay the trial because both sides will need time to evaluate results, a court official said. No date for the exam was set.

Mrs. Bobbitt, 24, will claim she was temporarily insane when she sliced off her 26-year-old husband's penis with a kitchen knife on June 23, said her attorney, James Lowe. Lowe didn't immediately return a reporter's telephone calls Friday.

At her husband's trial, Mrs. Bobbitt sobbed on the witness stand as she described two alleged rapes in the four days leading up to the mutilation.

She said she cut her husband as he slept, then fled their home clutching the severed organ. Police found it on a roadside where Mrs. Bobbitt flung it from her car window.

It was reattached surgically and doctors said Bobbitt is recovering well.

Mrs. Bobbitt faces up to 20 years in prison if convicted. She and her husband are seeking a divorce.