Newsarama reports that DC Comics, and its parent company Warner Brothers has full ownership on Superman.
Judge Otis Wright III of the U.S. District Court ruled that “The Court hold that the 2001 settlement agreement between DC and Siegels re-granted the Siegels’ Superman, Superboy, and a Superman advertisements that ran in the 1930s to DC in return for substantial advances and royalties,” and the motion of DC/Warner to end these litigations is granted. In other words, this give Warner/DC full ownership to the Superman character and other related properties including Supergirl and Superboy which were also part of the huge court battle.
The Superboy aspect of the case dates back to 1943 when Siegel pitched the story while he was in the Army during World War II. After litigation he and co-creator Joe Shuster were paid $94,000.
In 1997, the Siegels filed a copyright termination notice on DC, which Warner settled in 2001. The agreement was upheld by two courts in the past three months. The Siegels continued the fight, winning the Superboy case in 2006 and the full >Infinite Crisis, though he was later revived and a new Superboy comic started in 2011 during the New 52 launch.