In the first criminal case of its kind, a federal grand jury in Washington yesterday indicted chess star Bobby Fischer on a charge that he violated economic sanctions on Yugoslavia by playing former world champion Boris Spassky in Montenegro and Belgrade this fall.

Fischer, reportedly living in Belgrade and working on a book about the match, could not be reached for reaction, but he had already commented vividly on the sanctions and the possibility that the U.S. government might indict him before the match began on Sept. 2.

"This is my reply to the order not to defend my title here," he told reporters, spitting on a letter from the U.S. Treasury Department that warned him he could face a fine of up to $250,000 and/or imprisonment up to 10 years for "trading with the enemy."

"I don't support U.N. sanctions because ... I don't support the U.N.," he added.

The author of that letter, R. Richard Newcomb, the department's director of foreign assets control, said at a press conference yesterday that Fischer's own lawyers had come to him in July, asking for the U.S. position on the tournament. Then, Newcomb said, "they decided to ignore our written opinion."

Fischer's attorney, Joseph Choate of Los Angeles, did not return a call to his office yesterday.

U.S. Attorney Jay B. Stephens said his office had obtained an arrest warrant for Fischer and that his assistants were "exploring" the possibility of invoking an extradition treaty still in force between the United States and Yugoslavia.

After acknowledging that the treaty, even if it is honored by the controlling Serbian government, might not apply to such an economic crime and rejecting the possibility that the United States might kidnap Fischer, Stephens said his office would wait as long as necessary for Fischer, 49, to return.

"Mr. Fischer will face the choice of returning to the U.S. or being checkmated in Yugoslavia," Stephens said.

Fischer was charged with a criminal violation of the International Emergency Economic Powers Act, the law used by President Bush on June 5 to impose sanctions against Yugoslavia. By its terms, Bush's executive order prohibits anyone from entering into a contract "in support of a ... commercial ... project" in Yugoslavia. Stephens said yesterday that the indictment against Fischer is the first time the law has been used in a criminal prosecution.

Stephens also tossed aside questions from reporters who asked whether the indictment was more symbolic than substantive. Likewise, he suggested there was little concern that the case was a poor use of his office's resources while hundreds of murders and drug crimes wait to be prosecuted.

Stephens said this was simply a case of the federal government enforcing the sanctions. "You have violence {in Yugoslavia}, you have ethnic cleansing. ... The U.S. has acted to impose sanctions ... and they should be enforced," he said.

One federal prosecutor said he thought the case against Fischer might have a good deal of potential jury appeal. "People are really mad about Fischer playing over there for so much money," said the prosecutor, who asked not to be named. "And don't think the government won't play the tape of his spitting on the {Treasury Department's} letter to the jury, either."

The indictment could be the opening move in a game as complex as any Fischer has ever played in a career that made him the youngest U.S. champion in history, the youngest international grandmaster until recently, and the first and only American to win a world chess championship. A native of Brooklyn, he learned the game when he was 6 years old, soon lost all other interests and began beating adults with higher ratings. Long noted for abrasive and anti-social behavior, he refused to defend his world championship title after winning it in 1972 from Spassky and disappeared from the chess scene. For years he lived from hand to mouth in cheap hotels in and around Pasadena, Calif., with his chess books, computers and contacts with a few friends.

The Fischer case is beginning to resemble that of another erratic and anti-authoritarian American genius: poet Ezra Pound. Pound moved to Italy, became an enthusiast for Mussolini's government and made frequent broadcasts to American troops in Europe during World War II that the U.S. government considered treasonous. Captured by American soldiers at the end of the war, he was tried for treason, declared insane and confined for years to St. Elizabeths Hospital in the District of Columbia. Finally, because his continuing presence in an insane asylum was an international embarrassment to the U.S. government, he was released and allowed to return to Italy.

Fischer has several options: stay in Yugoslavia, where he is a cultural hero and has been offered luxurious accommodations; find another country willing to give him asylum and live on the $3.35 million he won for beating Spassky; or voluntarily return to the United States to stand trial.

Considering his fighting spirit, confrontational attitudes and deeply rooted sense of his ability to overcome enemies, it would not be out of character for Fischer to attempt to use the courtroom as a platform.