ALTON, Ill. (AP) — Contract negotiations in southwestern Illinois will resume with a federal mediator after a teachers union gave the Alton school district notice of a possible strike. The teachers’ union has twice rejected the Alton School District’s contract offer and voted last week to serve notice of a possible strike. The (Alton) Telegraph reports that negotiations are scheduled for Thursday afternoon. The contract dispute comes after a monthlong teachers’ strike in nearby East St. Louis kept more than 6,000 students out of school for 21 days in October. Classes in East St. Louis resumed Monday. The Alton school board has said it needs to trim a $2 million deficit, in part by having employees pay for a portion of health insurance premiums that are now fully covered by the district.