Karen Lewis says the Chicago Teachers Union will forgo the fourth, optional year of the contract that ended the 2012 teachers' strike.
That will mean the current contract will expire in June 2015, shortly after Chicago's mayoral election. Mayor Rahm Emanuel is expected to seek re-election.
It's been frequently reported Emanuel and Lewis have a strained relationship.
Lewis said Monday she is not looking to make anyone's election easy, adding "particularly someone who hasn't made our life easier."
Chicago Schools CEO Barbara Byrd Bennett said the district is "focused on finishing this school year strong," not next year's contract negotiations.
In a City Club of Chicago speech, Lewis promoted a tax on stock trades and other transactions to close a pension gap without cutting benefits for retired teachers
