Iran-Contra prosecutor Lawrence Walsh, stung by federal appeals court decisions setting aside Oliver North's three felony convictions, said he'll probably take the high-profile case to the Supreme Court.

In a 21-page decision issued Tuesday, the U.S. Court of Appeals for the District of Columbia Circuit denied Walsh's request to reinstate North's three convictions, but rewrote part of its previous decision to concede that North's jury may have been given confusing instructions.The decision is a blow for Walsh and may jeopardize the conviction of another Iran-Contra defendant, former national security adviser John Poindexter.

Walsh released a statement Tuesday saying an appeal to the Supreme Court is likely to be his next course of action.

North, a retired Marine lieutenant colonel and former National Security Council staff member, was convicted May 4, 1989, of three criminal charges stemming from his involvement in an elaborate scheme to sell arms to Iran and funnel the profits to Nicaraguan Contra rebels at a time when such aid was banned by Congress.