WHITE PLAINS, N.Y. (AP) _ A Swiss nanny acquitted in the arson murder of an infant says she has decided not to pursue a $20 million lawsuit against authorities so she can put ''the horrible experience behind me.''

Olivia Riner, of Wettingen, Switzerland, said she was going to be 21 years old and wanted a career.

''I want to put that horrible experience behind me. ... I don't want to relive the horror,'' she wrote in a letter to her attorneys in New York.

Riner had been charged with setting fire to the Thornwood home of William and Denise Fischer on Dec. 2, 1991 - one month after she arrived to care for the couple's 3-month-old daughter, Kristie.

The infant died in the fire, which destroyed the house near the New York City suburb of Mount Pleasant. Flammable liquid was found on the baby's diapers, investigators said.

Riner was acquitted of murder and arson and returned to Switzerland.

In October, Riner's lawyers filed a notice of claim with the state, county and city of their intention to sue, alleging police investigators overlooked evidence that could have cleared her. In New York, a notice of claim must be filed 90 days before a lawsuit.

Louis Brevetti, Riner's civil attorney, said she is working as a physician's assistant in Switzerland.

Mount Pleasant police say they are investigating the murder and arson but have made no arrests.