Attorney General William French Smith twice rejected offers by lawyers for John W. Hinckley Jr. to have Hinckley plead guilty to charges that would have sent him to prison, insisting on a trial. Hinckley subsequently was found not guilty by reason of insanity and sent to a mental hospital.

The offers on behalf of Hinckley came in meetings with Charles F.C. Ruff Jr., then U.S. attorney for the District of Columbia, and Assistant U.S. Attorney Roger M. Adelman, who prosecuted the case. One offer came before Hinckley's indictment last August on charges of shooting President Reagan and three others, and the other offer was made after the indictment.

"On two occasions, they the plea bargaining offers went to the attorney general. It was the attorney general's position they were totally unacceptable," a Justice Department official who asked not to be named said yesterday.

The official would not discuss exactly what Hinckley's lawyers were offering or whether Ruff recommended accepting the pleas. "We will generally plea bargain, but want it to be commensurate with the crime committed," the official said.

One participant in the negotiations said that Hinckley's lawyer, Vincent J. Fuller, offered to have Hinckley plead guilty to assaulting all four individuals.

In return, Fuller wanted an agreement that the Justice Department would recommend that Hinckley serve his prison sentences concurrently and that the judge set a date when Hinckley could be considered for parole.

In addition, the source said, Fuller wanted Hinckley sent to one of several prisons where psychiatric care is available.

If the pleas had been accepted, Hinckley could have been sentenced to life in prison, but could have been eligible to be considered for parole at an agreed-upon date. He would have had to serve at least 10 years, the source said.

In meeting with Fuller and other defense lawyers, the source said, prosecutors made it clear they would have to "go up the ladder" at the Justice Department before they could accept the offer. They came back and said "they would not bargain," the source said.

The discussions took place in May and November last year. Hinckley's lawyers offered to have him plead to charges that carried maximum penalties of life in prison--either attempting to assassinate a president or assault with intent to kill, the source said.

The rationale behind the offers, according to the source, appeared to be that Hinckley would have had no hope of being released if he were sentenced to consecutive terms involving all four victims.

On the other hand, if Hinckley got concurrent terms and prosecutors recommended an agreed-upon date for parole consideration, he would have had a chance to get out some day.

The source said that although Hinckley's parents were not consulted, the prospect of parading the family's personal history and Hinckley's own problems before the nation was one of the considerations that prompted defense lawyers to make an offer that would avoid a trial.

They made a third, less serious attempt to plea bargain for Hinckley after Stanley S. Harris became U.S. attorney, but the offer never got to the attorney general, the Justice Department official said.

A spokesman for Smith had no comment yesterday on whether such an offer was made and what role, if any, the attorney general played in the events leading to the trial.

Last month, a jury found Hinckley, 27, not guilty by reason of insanity of attempting to assassinate Reagan, presidential press secretary James S. Brady, Secret Service agent Timothy J. McCarthy and D.C. police officer Thomas K. Delahanty outside the Washington Hilton Hotel on March 30, 1981.

The verdict set off a barrage of criticism of the legal system that would allow Hinckley, who admitted the shootings that were vividly captured on videotape, to be sent to St. Elizabeths Hospital.

U.S. District Judge Barrington D. Parker ruled during the trial that Hinckley should be tried under provisions of federal law, which require prosecutors to prove that the defendant is sane.

In tesimony earlier this week before the Senate Judiciary Committee, Smith called for changes in federal law to eliminate the insanity defense.

Under the legislation supported by Smith, "Mental disease or defect would constitute a defense," he said, "only if the defendant did not even know he had a gun in his hand or thought, for example, that he was shooting at a tree."

If the measure were law, a criminal trial such as Hinckley's would no longer be "a time-consuming, confusing swearing contest between opposing psychiatrists," Smith told the committee.

Last Thursday, columnist Jack Anderson reported on the ABC television network's "Good Morning America" show that Hinckley had offered to plead guilty and Smith had rejected the offer. The report went unconfirmed, although Ruff said several reporters had called him to ask if such an offer had been made and he declined to comment.

Hinckley himself has said in telephone interviews with The Washington Post that he was shocked at the verdict. "I thought for sure I would be convicted because of the pressure the jury would be under to return a guilty verdict," he said from St. Elizabeths, where he has the right to request a hearing on his mental condition every six months.