High-stakes comic book battle comes to an end

Who owns Iron Man and Captain America? Is it Walt Disney (DIS) subsidiary Marvel Entertainment, which has made big profits from the characters in comic books and movies, or is it comic book legend Jack Kirby, who helped create the characters decades ago?

That question has been at the center of a prolonged legal battle between the comic book company and Kirby's heirs. And just as the case appeared headed to the U.S. Supreme Court, both sides have decided to settle. The financial amount of the settlement has not been disclosed.

The case began when Kirby's children -- Lisa, Neal, Susan and Barbara -- filed in 2009 with the U.S. Copyright office to take back the rights to some of Marvel's biggest characters, including the Avengers, X-Men, the Fantastic Four and this year's breakout star, Groot.

Kirby, who died in 1994 at age 76, helped create the characters while working as a freelance comic book artist from 1958 to 1963, but what share of credit he was due remains unclear.

Marvel reportedly attempted to negotiate a settlement with Kirby's heirs after they made the claims, but sued the family when those talks faltered. The response from the courts since then has largely come down against the family's claim. Lower courts have repeatedly decided that because Kirby had been working for Marvel, the copyrights belonged to the company, Reuters reports.

Kirby's family continued to press the case, however, and petitioned the Supreme Court to review the issue. Copyright law does address work-for-hire situations, largely giving ownership to the companies. But Kirby's work occurred before the Copyright Act of 1976, and prior copyright law, the Copyright Act of 1909, didn't give enough clarity on the issue, according to an analysis by The Comics Journal.

This isn't the first time ownership of a comic superhero has been debated. A 2008 court decision gave a share of the Superman copyright to the heirs of Jerome Siegel, who 70 years earlier had sold the rights to Detective Comics for $130. That ruling was later overturned, however, when the courts reinstated the rights to Warner Bros and subsidiary DC Comics.

By agreeing to a settlement, both sides in the Kirby case can now move on. Marvel, which can seemingly do no wrong with comic-related movies, an idea hilariously spoofed this weekend in this "Saturday Night Live" skit, is free to focus on a sequel to its smash hits "The Avengers" and "Guardians of the Galaxy."

Indeed, the company's three "Iron Man" movies have grossed $2.4 billion in box-office receipts globally, according to Box Office Mojo. That doesn't count Blu-ray and other video sales.