WASHINGTON (AP) _ A federal appeals court on Wednesday ordered an indefinite postponement of a trial on a Jewish Holocaust victim's suit against Germany for a $500 monthly war reparations pension.

Circuit Court Judges Patricia Wald and Ruth Ginsburg said the trial on a suit by Hugo Princz, 71, of Highland Park, N.J., cannot take place until the appeals court resolves Germany's claim of sovereign immunity.

Germany, meanwhile, has effectively offered Princz a one-time payment of up to $3,500 and a monthly pension of between $195 and $300 beginning in August 1995, attorneys for the Bonn government said Wednesday.

Steven Perles, Princz' attorney, called the offer ''unsatisfactory'' in court papers and said later in an interview the amount ''won't even cover the Xerox costs'' spent over the past seven years pressing his client's claim.

However, Germany's attorney in the case, Peter Heidenberger, made it clear that is the only offer Princz is going to get in the wake of the appeals court decision.

''That's the compensation the German government has agreed to pay under the program,'' Heidenberger said. ''You cannot pass a separate law for every individual.''

The appeals court decision was a victory for Germany, effectively taking the case away from U.S. District Judge Stanley Sporkin for between six and 18 months. Sporkin, who also is Jewish, had rejected Germany's claim of sovereign immunity last December.

And last week Sporkin refused to postpone the scheduled May 26 trial, saying it ''would be one of the greatest ironies ... to permit Germany to win in the U.S. courts what it lost on the battlefield.''

Germany has asked Sporkin, who is Jewish, to disqualify himself from the case, saying his ''outrage'' from the bench during the December hearing ''reflect ''antagonism and animosity'' toward Germany.

During that hearing, Sporkin referred to Nazis as ''animals.'' At another hearing Wednesday, he asked Germany's attorneys if anybody in the Bonn government had any ''morality.''

Princz filed the suit 13 months ago, claiming that Germany for 38 years has unjustly denied him a war reparations pension after enslaving him for three years during World War II and murdering everyone else in his family.

At the outbreak of World War II, Princz and his family were trapped in German-occupied Czechoslovakia, where his father, an American citizen, operated a farm machinery leasing business.

In its court responses, Germany apologized for the ''persecution'' that Princz suffered but said he is ineligible because he was an American citizen at the time rather than one of the tens of thousands of European refugees freed from concentration camps at the end of the war.

However, after a rancorous hearing in December before Sporkin, the German Finance Ministry said last week it would have no objection to Princz seeking a claim under a new $609 million fund established last October for East European refugees.

Too little and too late, replied Princz' attorneys, who contend in their suit that Princz is entitled to restitution for the monthly benefits dating back to 1955, when his first pension application was rejected, plus $5 million in punitive damages.

''We'll proceed with the appeal, ask for expedited consideration and deal with the problem,'' Perles said Wednesday. ''My client will be 72 in November. Obviously any delay is a serious one for a person of his age.''

The State Department, meanwhile, on Tuesday advised the German Embassy in Washington that it and the Justice Department may enter the court fray. ''The department wishes to express its strong view that Mr. Princz' legitimate and compelling claims be resolved,'' a State Department legal adviser said in a memo to Germany's ambassador.