KTVA-TV general manager Jerry Bever said an internal investigation showed the recording left accidentally on the phone of Miller's spokesman involved how a Miller rally headlined by Palin might be promoted.
Bever said the "ensuing dialogue went downhill from there."
He couldn't immediately be reached to say if the producers had been fired.
Bever earlier said the discussion centered on "what if" scenarios for covering the rally last week and that the recording's contents had been taken out of context.
Miller's camp claimed that station staff were discussing making up stories about Miller. A Miller spokesman had no immediate comment.