A federal appeals court panel today blocked U.S. District Court Judge David N. Edelstein from continuing an inquiry into conflict-of-interest charges he has raised against Assistant Attorney General William Baxter following Baxter's decision to drop the government's antitrust suit against International Business Machines Corp.

The extraordinary order was issued as a writ of mandamus, a method primarily used by courts to overturn abuses of judicial authority. Edelstein, the judge who heard the 13-year litigation, had scheduled a hearing for Monday on the allegations.

IBM and the government had asked the federal appeals court here to block the proceeding and a related inquiry that Edelstein is holding on whether congressional antitrust legislation gives him the power to study the closing of the case. Both sides contend that, in fact, there is no matter whatsoever before Edelstein.

The Justice Department disclosed on Thursday that its internal investigation into the Baxter question had cleared the Antitrust Division's chief of any impropriety, and the appeals court acknowledged that finding in its order. The appeals panel concluded that there "is not even colorable jurisdiction" in the District Court to pursue the conflict-of-interest issue.

But the appeals court did not rule on the question of the judge's power to study the closing of the case.

Instead, it affirmed Edelstein's authority to continue evaluating that question and "acting upon any other request for relief sought in this litigation" by either party.

Lawyers for Washington philanthropist Philip Stern and a legal group affiliated with Ralph Nader have argued that Edelstein has the authority under the law to look into the circumstances surrounding the Jan. 8 closing of the landmark suit.