SEATTLE (AP) _ Union bus drivers voted to strike Saturday, leaving about 12,000 students to find alternative transportation to the city's public schools.

Members of Teamsters Local 763 rejected the latest contract offer from Laidlaw Transit Inc. after the two sides couldn't reach an agreement on a pension plan, union members said. Talks broke down earlier this week, despite federal mediation.

Laidlaw's 300 drivers, who operate 275 buses, operate primarily in the north Seattle area.

The Toronto-based Laidlaw holds a contract to bus half of the district's 24,000 students. The drivers had been working without a contract since September.

``I can just see kids stranded on street corners,'' said Barbara Schaad-Lamphere, president of the Seattle Parent and Teacher and Students Association. ``So many rely on bus transportation; parents will be flabbergasted.''

The district will issue city bus tokens to middle and high school students to get to school. Students too young to ride the bus will have to be driven.