The 9th Circuit heard two appeals Tuesday that could decide the bitter 15-year-old legal battle for control of the Man of Steel.

An attorney for DC Comics asked the three-judge panel to reverse a 2008 decision granting the heirs of Superman co-creator Jerry Siegel his portion of the copyright to Action Comics #1, arguing the family is reneging on a 2001 agreement that would have ensured the company's ownership of the billion-dollar property.

DC has long argued that Siegel's daughter Laura Siegel Larson walked away from a settlement deal that would've allowed the company to retain all rights to Superman in exchange for $3 million in cash and contingent compensation worth tens of millions. The publisher claims the heirs only withdrew from the settlement after attorney Marc Toberoff entered the picture, falsely asserting he had a $15 million offer for the rights from a billionaire investor (alleged to be Hollywood super-agent Ari Emanuel, brother of Chicago Mayor Rahm Emanuel). However, a federal judge determined in 2008 that, without a formalized contract, there was no agreement.

According to Law360, Toberoff told the court on Tuesday that while both sides "had a deal in principle," there was no “meeting of the minds” and, therefore, no binding contract. When judges Sidney R. Thomas and Stephen R. Reinhardt referred to an Oct. 19, 2001 letter from Larson's then-attorney stating she “accepted DC Comics' offer,” Toberoff countered that "the publisher cannot point to an acceptance of the terms of the Oct. 19 letter."

Businessweek reports that DC's lead outside counsel Daniel Petrocelli told the panel that, "at the very minimum," his client is entitled to a trial regarding whether the two parties had an agreement. "This has the potential to dispose of the entire dispute,” he said. If the contract is found to be valid, Petrocelli asserted DC would immediately pay Larson $20 million in exchange for Siegel's share of the Superman copyright.

In the second case, Toberoff urged the court to dismiss DC's 2010 lawsuit accusing him of orchestrating “a web of collusive agreements” that led the Siegel and Shuster families to reject “mutually beneficial” longtime deals with DC and seek to recapture copyright to the Man of Steel. Last year Toberoff failed to convince a federal judge to reject the claim under California's anti-SLAPP law designed to curb lawsuits intended to intimidate the opposition through delays and legal expense.

DC's lawyers argued that Toberoff's actions aren't protected by free speech because he wasn't acting as an attorney, but rather as a "Hollywood businessman," and that the $15 million offer for the Superman rights was fraudulent.

Tuesday's hearing arrived less than three weeks after a federal judge ruled the Shuster estate surrendered the ability to reclaim its 50-percent interest in the Man of Steel in a 1992 agreement with DC. That leaves the publisher and the Siegel heirs sharing ownership of the property -- dependent, of course, on the outcome of this case and a likely appeal in the Shuster decision.