A federal appeals court refused to dismiss charges Friday against Oliver North and two other defendants in the Iran-Contra case, ruling it lacked the power to hear their legal claims until after a trial is held.

A three-judge panel of the U.S. Circuit Court of Appeals for the District of Columbia, voting unanimously, said it is premature to entertain the appeal by North, former national security adviser John Poindexter and Iranian-born businessman Albert Hakim.The ruling was a major setback to the men and especially to North, who is to be the first to go on trial for his role in the covert operation that saw profits from the sale of arms to Iran diverted to the Nicaraguan rebels.

The three were indicted March 16 along with former Air Force Maj. Gen. Richard Secord on charges of conspiracy to defraud the government. Poindexter and North, a former National Security Council aide, also were charged with obstruction of justice.

Lawyers for North, Poindexter and Hakim had asked the appeals court to dismiss the charges on grounds the grand jury that indicted them was improperly influenced by testimony they gave to Congress during its 1987 hearings into the affair.

The three testified under limited immunity, which meant that statements they made could not be used against them in the criminal investigation led by independent prosecutor Lawrence Walsh.

In a June decision, one of the orders by the lower court challenged by the defendants, U.S. District Judge Gerhard Gesell rejected the defense argument that the case should be dismissed because the prosecution improperly used protected testimony by the defendants during congressional hearings.

Gesell has ordered separate trials for the four men and in early July set a Sept. 20 trial date for North. But the judge, in an order issued August 5, delayed the trial until after the presidential election in response to complaints from North's attorneys, who accused the judge of being in a "frantic rush" to go to trial.