A "very distressed" Bernhard Goetz walked out on a grand jury in a disagreement over how much immunity from prosecution he should receive, forgoing his chance to testify about the December shootings of four youths on a subway train.

Goetz's lawyers said prosecutors were trying to "stack other charges" against him. The district attorney's office said Goetz wanted to limit the inquiry "unreasonably and unfairly."

Goetz was indicted in January on firearms charges rather than on attempted-murder charges. Manhattan District Attorney Robert M. Morgenthau, citing a new witness, submitted the case to a new grand jury March 13.

In a letter to the grand jury foreman, Goetz said he was willing to waive immunity from prosecution for anything he said about the events of Dec. 22, the day of the shootings.

But his lawyer, Barry Slotnick, said, "The district attorney refused [Goetz's] waiver of immunity and indicated that he wanted to question him about anything and everything that he so desired," including "purchases of guns in Florida. And it was our impression, quite clearly, that he was looking to stack other charges" against Goetz.

Goetz was "distraught" over his inability to testify, Slotnick said. "He was ready. It was painful for him . . . . He was very, very distressed. He was speechless."