Butler Hospital and the union representing more than 700 nurses, mental health workers, dietary and maintenance staff announced Monday that they have reached a tentative agreement to end the three-month long strike. “On behalf of both Butler Hospital and members of the bargaining committee representing all job classifications of the hospital, we are pleased to share that a tentative agreement has been reached,’’ reads a joint statement posted on the hospital’s website. Union members are scheduled to vote on the agreement Monday, a union spokesperson confirmed. In return, union leaders said, they were asking the hospital for another $1.2 million in wages over four years – about $300,000 a year. And Butler Hospital announced that due to short-staffing it was shutting down 29 beds in its addiction treatment unit.