The two genre series have formed a successful pairing on Thursday nights but Smallville will move to a less desirable 8pm slot on Fridays for its ninth - and most likely final - season.
Joining Supernatural on Thursdays is new drama The Vampire Diaries, starring Ian Somerhalder as one of two vampire brothers vying for the affections of a 17-year-old girl.
Melrose Place is being teamed with fellow remake 90210 on Tuesdays, while Gossip Girl and One Tree Hill are continuing in their Monday night slots. The network has neglected to pick up the proposed Gossip Girl spinoff, featuring Serena's mother, Lily Van Der Woodsen.
Wednesday night is becoming a fashion double, with America's Next Top Model leading in to new Mischa Barton-fronted supermodel drama The Beautiful Life.
New drama Parental Discretion Advised, about a girl in foster care who decides to become an emancipated minor, is being saved for midseason.
Notable axings include Everybody Hate Chris, Privileged, Reaper and The Game.
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