John W. Hinckley Jr.'s trial took an unexpected jump toward conclusion yesterday as the chief prosecutor announced the government will rest its case today.

The prosecution's surprise decision means that U.S. District Judge Barrington D. Parker must now decide whether to allow the defense to present final additional evidence before the case is handed over to the jury, which has heard six weeks of testimony. The possibility that Hinckley will take the witness stand in his own defense has not been ruled out.

Hinckley became increasingly restless during yesterday's court session and at one point, when a government psychiatrist testified she did not believe he shot President Reagan to win the love of the actress Jodie Foster, Hinckley retorted aloud: "You're wrong."

Later, he glared at the psychiatrist, Dr. Sally A.C. Johnson, and several times mouthed obscenities at her, appearing to say: "Go to hell," and "I hate you, bitch." The jurors were in the courtroom at the time but it was unclear whether they noticed Hinckley's actions.

Parker did not hear Hinckley's comment on Johnson's testimony, but was informed about it by a court official. He did not appear to be aware of Hinckley's inaudible comments, which occurred while Parker was involved in a conference with lawyers from both sides.

At the conclusion of the day's proceedings, the judge summoned Hinckley to the courtroom lectern and scolded him for speaking out, telling him his behavior "is not to be condoned.

" . . . I do not intend to let it go unnoticed nor do I intend to see it repeated . . . Do you understand what I am saying?" Parker asked Hinckley.

"Yes, I do," Hinckley responded, standing with his hands clasped behind his back. He was then led from the courtroom by deputy U.S. marshals.

Johnson, who interviewed Hinckley 55 times in the four months after the shootings, completed 21 hours of testimony yesterday, saying that she believed that Hinckley was in control of his behavior when he wounded Reagan and three others outside the Washington Hilton Hotel more than a year ago.

It had been expected that the prosecution would call two more psychiatric experts to support its argument that Hinckley was sane at the time of the shootings.

At the close of yesterday's session, however, Assistant U.S. Attorney Roger M. Adelman said the government wanted to introduce into evidence a chart of Hinckley's travels, then abruptly declared that the prosecutors intended to rest their case today without further testimony.

"What did you say?" asked Parker, clearly taken aback by Adelman's announcement. Adelman said prosecutors had been reviewing their case as the evidence was presented and had concluded it would be "prudent" to bring it to a close now. With a smile, he turned and sat down.

Hinckley's chief defense lawyer, Vincent J. Fuller, admitting he was "taken a bit by surprise," said he nevertheless wanted Parker to decide whether the defense could now present additional evidence to the jury, to counter points raised by the government.

Fuller indicated the defense wants to call two witnesses, neither of whom was identified. Details on the defense request, which the government opposes, were given to Parker under seal. A hearing on the issue is expected today.

Depending on what happens in that hearing, the jury could begin its deliberations by the end of the week.

Before the jurors left the courthouse yesterday, Parker informed them that he plans to sequester them in a local hotel during the course of their deliberations. During the trial, the jurors have been permitted to return home each evening.

Parker told the jurors he decided to sequester them to make sure that nothing happened during their deliberations "that would cause this whole proceeding to go askew in any manner."

The jurors, including six alternates, have been attentive during long days of often tedious testimony. Lately however, some have appeared distracted, occasionally looking around at other activity in the courtroom.

Prosecutors have presented testimony from Johnson, a staff psychiatrist at the federal correctional institution at Butner, N.C., and from Dr. Park Elliott Dietz, an associate professor of psychiatry at the Harvard medical school. Both told the jury they believed that while Hinckley suffered from personality disorders when he shot Reagan, he knew his actions were wrong and could have abided by the law.

Johnson was seen as a key witness for the government, since she had interviewed Hinckley about his state of mind within four days after the shooting. Prosecutors established yesterday that Hinckley had said Johnson and a psychologist at Butner, Dr. James Hilkey, "knew him best and had the most accurate account of the story."

The defense presented testimony from three psychiatrists, all of whom told the jury that Hinckley suffered from forms of schizophrenia, a serious mental illness, characterized by a severe break with reality. They testified that Hinckley was unable to control his behavior when he shot Reagan, and had no emotional appreciation that his acts were wrong.