FARMINGTON – A 44-year-old Farmington woman pleaded guilty Monday to drunken driving but had a manslaughter charge dropped in a plea agreement with prosecutors.

Sarah Forbes was allegedly drunk when her sport utility vehicle struck and killed a snowmobile passenger in February. A jury trial was set to get under way Monday in Franklin County Superior Court.

Lisa Cerqueira, 20, was fatally injured when she was struck by Forbes’ SUV while sitting on a disabled snowmobile. Cerqueira and her fiance, Rick Billian, had crossed Routes 2 and 4 to reach the other side of a snowmobile trail when their snowmobile got stuck on a curb and Billian got off to straighten its skis.

The state entered into the plea agreement with Forbes over the objections of the victims’ families, according to the Sun Journal of Lewiston’s Web site.

The newspaper said a state Department of Health and Human Services witness would have testified that Forbes’ blood-alcohol level was 0.23 percent – nearly three times the legal limit – when a sample was taken at a hospital.

Forbes faces up to 10 years in prison when she is sentenced Wednesday.