A federal judge yesterday reversed the Senate's 1989 conviction of U.S. District Judge Alcee L. Hastings on corruption charges, ruling that Hastings was tried improperly by a committee instead of the full Senate.

The decision, written by U.S. District Judge Stanley Sporkin, marks the first time a Senate conviction has been overturned by a federal judge. Lawyers for the Senate had argued strenuously that Sporkin lacked authority to review the Senate's action, but Sporkin disagreed.

"To say that impeachment trials are wholly the province of the legislative branch does not mean that the judicial branch can never reach any issue that involves impeachment," Sporkin said in his opinion. "Independence is not isolation."

Sporkin's ruling does not restore Hastings to the federal bench; its practical effect is to order a new trial before the full Senate, but the judge noted in his order that the case almost certainly will reach the Supreme Court and he stayed the ruling pending appeal.

The Supreme Court has accepted an appeal from another former federal judge, Walter L. Nixon Jr., of Mississippi, who also was convicted by the Senate in 1989. In Nixon's case, however, he had been convicted in 1986 of lying to a federal grand jury investigating allegations that he had accepted a gratuity in exchange for influencing a state criminal prosecution.

Hastings had been acquitted by a jury of bribery and conspiracy charges. The Senate found that he had engaged in a "corrupt conspiracy," the only time a federal official has been removed from office for misconduct that had not also resulted in a criminal conviction by a trial jury.

Hastings's challenge to his Senate conviction is based on a simple argument. He maintains that the full Senate must hear the evidence about him and return a verdict, instead of a 12-member Senate committee whose work was ratified by a Senate vote.

Sporkin agreed.

"Without depriving the House or the Senate of one iota of their exclusive constitutional powers to impeach, try and convict . . . this court has jurisdiction to interpret what the Constitution says about impeachment," Sporkin said. "It states that the accused officer is entitled to a trial. This means a trial by the full Senate. . . . He is entitled to have one."

Hastings, currently locked in a primary runoff election for a Florida congressional seat, said the ruling was "very exciting."

"It feels real good to have some kind of victory in this matter. For the most part, we lost all the way up the ladder."

Hastings said he has decided not to return to the federal bench even if he is ultimately successful in this case. "I'm elated that the matter will go before the Supreme Court, and I'm hopeful that the court will put the matter at rest. All of us in this country need to know what impeachment means," he said.

Hastings mused that, if he wins both his election and his appeal, he could be working on Capitol Hill if the Senate acts again on his impeachment.

"Wouldn't it be more than poetic justice to win a congressional seat and appear before the full Senate in a trial?" he said.

Hastings ran second in the Democratic primary for Florida's newly created 23rd Congressional District, in which black voters have a plurality. The district stretches from north Dade County to Fort Pierce.

The runoff election is Oct. 1. Hastings said that, in an odd way, the impeachment controversy may help him. "I have maintained that I did nothing wrong, and I didn't do anything wrong," he said.