(Reuters) - The billionaire hedge fund manager Leon Cooperman has asked a federal judge for permission to immediately appeal a ruling that, if overturned, could spell the end of the U.S. Securities and Exchange Commission’s insider trading case against him.

FILE PHOTO: Leon G. Cooperman, CEO of Omega Advisors, Inc., speaks on a panel at the annual Skybridge Alternatives Conference (SALT) in Las Vegas May 7, 2015. REUTERS/Rick Wilking/File Photo

Cooperman and his firm Omega Advisors Inc are seeking to reverse a March 20 ruling that let the SEC pursue civil claims that Cooperman and Omega reaped about $4.09 million of profit in 2010 by trading in Atlas Pipeline Partners LP based on confidential tips from an Atlas executive about a planned asset sale.

The SEC did not immediately respond on Wednesday to requests for comment.

Cooperman, 73, has argued that the case should be dismissed because the SEC could not show he had agreed not to make trades before receiving confidential information.

But in the March 20 ruling, U.S. District Judge Juan Sanchez in Philadelphia said the SEC could pursue claims that Cooperman “misappropriated” information despite the apparent absence of a prior agreement not to trade.

In a Tuesday filing, Cooperman’s lawyers called that theory “aggressive and untested,” saying no insider trading case had ever been premised on a post-disclosure agreement - here, an oral agreement by Cooperman - to keep information confidential.

The lawyers asked Sanchez to certify an appeal of his ruling to the federal appeals court in Philadelphia, saying a decision in Cooperman’s favor would result in a dismissal and avoid a scheduled Nov. 6 trial.

They also said the fraud charge, “even if ultimately not proven at trial, has caused and will continue to cause serious harm to Mr. Cooperman’s reputation and Omega’s business.”

Omega said its assets under management have fallen to about $3.6 billion as of March 31, from about $5.4 billion when the SEC sued in September.

In a Monday court filing, Cooperman and Omega said they “deny that they engaged in any wrongful, illegal or improper conduct, and aver that each of them is innocent.”

Cooperman maintained in a Wednesday interview on CNBC television that the SEC case was “without merit.”

Along with Galleon Group’s Raj Rajaratnam and Steven A. Cohen’s SAC Capital Advisors LP, Cooperman is one of the most prominent recent targets of U.S. insider trading probes. He is worth $3 billion, according to Forbes magazine.

The case is SEC v Cooperman et al, U.S. District Court, Eastern District of Pennsylvania, No. 16-05043.