The chess match between Victor Korchnoi and Boris Spassky has been interrupted in Belgrade by a dispute between the two players. Spassky, who is trailing by a score of 6 1/2 to 3 1/2, did not show up for the 12th game, which was scheduled to be played today, and tournament officials are deliberating on what steps to take. Technically, they could award the game to Korchnoi on a forfeit.

Spassky has been refusing to sit at the playing table since Game 10, which began last Friday and has not yet been finished. He complained that eye trouble made it difficult for him to concentrate at the chessboard and that the pieces being used (which he originally had chosed) were "too shiny." The pieces were changed, but Spassky has continued to sit in a private cubicle, studying the position on a large, electronic demonstration board which was set up for spectators. He would approach the playing table only to make his moves.

Korchnoi complained of this conduct, some fans walked out in protest, and as a result the continuation of Game 10, originally scheduled for last Tuesday, was postponed until today. Meanwhile, the demonstration board on which Spassky had been studying the game was removed, and Spassky protested by not showing up for Game 12 yesterday.

It is not certain whether Spassky will agree to continue Game 10 today, or whether the tournament officials will award Korchnoi a point because of Spassky's refusal to begin Game 12 on time yesterday.