Warner Bros has won commercial control of Superman, ending a long legal wrangle with the heirs of the comic-book hero's creators, Joe Shuster and Jerry Siegel.
A United States appeals panel has unanimously ruled the heirs must abide by a 2001 letter accepting Warner's offer for their 50% share of Superman, the BBC reports.
The ruling undoes a 2008 court decision that gave Mr Siegel's family control of key components of the Superman story, including his costume.
The latest Superman film, Man of Steel, is due to be released later this year.
Writer Jerry Siegel and artist Joe Shuster created the comic book superhero in 1932.