The jury in the political corruption trial of Gov. Marvin Mandel failed to reach a verdict again today, after passing up an offer by the judge to answer questions that might break the deadlock that remains after 112 hours of deliberation.

Instead they quit their windowless deliberation room, where they have been cooped up for 12 days at 5:45 p.m., returning to their suburban motel at the earliest hour since last Thursday.

During a hearing this morning attorneys for both defense and prosecution proposed additional solutions for the jury's inability to reach a verdict, but the judge indicated he wanted to wait for the jury's response to his offer before taking further action.

U.S. District Court Judge Robert L. Taylor, in a six-minute talk to the jury this morning, offered to answer any questions jurors might have about the law, to restate his explanation of the charges of mail fraud and racketeering, or to have read to them any part of the testimony.

Foreman Howard O. Davis indicated that the jury of seven men and five women wanted to return to their room just off the main courtroom to write down their questions. That was at 10:20 a.m. But the jurors remained incommunicade for the rest of the day, as they have for nearly all of the time since receiving the case almost two weeks ago.

Although Judge Taylor rejected suggestions from both the prosecution and defense for further action today he did indicate his impatience with the lack of a verdict. "How long do you think we can stay here day after day?" he asked the lawyers.

Arnold M. Weiner, Mandel's lawyer, asked Taylor to poll the jury on "whether there is reasonable hope or expectation" of a verdict.

Public defender Charles G. Bernatein, representing codefendant Ernest N. Cory Jr. asked that the judge "declare a mistrial now." Bernstein said "I honestly fear that keeping them locked up itself can be coercion.

I think they have been out long enough." Weiner added that "both the integrity and credibility" of any verdict finally delivered would be in question.

Federal prosecutors, however, opposed both polling the jurors and declaring a mistrial. They asked the judge instead to employ stronger language in urging the jurors to reach a decision by asking those in the minority to listen carefully to the views of those in the majority.

The judge said he prefers to let the lury make the next move, reserving a stronger charge for his "very last action" before declaring a mistrial. It was apparent from a remark made by the judge that he thought the jury would come back quickly today with at least some questions. At the end of the session this morning he asked the lawyers to "take a short recess, gentlemen."

The jurors appeared not have been prepared for a public appearance today, further adding to widespread speculation that they remain far from a unanimous decision. Most were casually dressed including foreman Howard Davis, a Frostburg engineer who normally wears a suit and tie, but who wore neither today. Some of the other jurors wore blue jeans and beach thongs.

Today was the first time since last Wednesday that they had appeared in court. They looked tired and all nodded assent when asked by the judge if they wanted to return to the jury room to continue deliberations or discuss their questions in open court.

After the 75-minute hearing, Mandel told reporters that "any verdict" delivered after such a long time would have "extreme difficulty" being accepted. Last week, Mandel said he would view a hung jury as vindication because of the long hours expended without a conviction.

The governor also said he agreed with a suggestion proposed in court by William G. Hundley, attorney for codefendant W. Dale Hass, that if the judge again urges the jury to come to a decision that he also set a deadline for them to reach a verdict.

"The judge, jury, everyone has been under extreme pressure," Mandel said. "Setting a time limit . . .would bring it to a conclusion one way or another."

Later today the prosecutors gave the judge a memo asking that he resubmit to the jury details of the federal mail fraud statues, a key ingredient in the government's charge that Mandel and codefendants Hess, Cory, Irvin Kovens and brothers William A. and Harry W. Rodgers III were engaged in a scheme to defraud the people of Maryland.

Mandel lawyer Weiner said defense attorneys will oppose that request because "It proceeds from the premise that (the jury) didn't understand the instruction. The jury didn't say that."

Judge Taylor said that if none of the lawyers objected he might ask the jurors in open court if they thought they could reach a verdict. But chief prosecutor Barnet D. Skolnik objected, saying that if the jury does not send out any new notes, "the inference should be drawn that it is making some progress."

Skolnik said that trials that were shorter than the 10-week Mandel case have resulted in longer deliberation that produced verdicts. He said that any inquiry from the judge about the jury's progress might be interpreted as an invitation to quit.

Noting that the jurors "have not been home for 2 1/2 months." Skolnik said that asking them how close they were might result in "the temptation . . .to put their duty aside and just have an end of it and go home."