Two former executives of Adelphia Communications Corp. who are already serving lengthy prison terms for a massive fraud that led to the company’s demise have won a significant court victory that could lead to the dismissal on double jeopardy grounds of the conspiracy charges in a second indictment against them.

The 2-1 ruling by a federal appeals court in Philadelphia comes less than three weeks after the same pair suffered a major setback as a federal appeals court in New York upheld their stiff sentences.