NEW YORK (AP) — A New York federal appeals court has dealt a blow to the government's approach to insider trading cases by reversing two convictions.

The 2nd U.S. Circuit Court of Appeals on Wednesday overturned the convictions of Anthony Chiasson, of Manhattan, and Todd Newman, of Needham, Massachusetts.

Chiasson co-founded Greenwich, Connecticut-based Level Global Investors. He was sentenced to 6½ years in prison.

Newman worked for Stamford, Connecticut-based Diamondback Capital Management. He received 4½ years.

The former portfolio managers were both convicted in December 2012.

The appeals court said the government failed to present sufficient evidence the men willfully engaged in insider trading or conspired to break the law.

The reversals could jeopardize the insider trading conviction of former SAC Capital portfolio manager Michael Steinberg, which is being challenged on the same principle.