The jury in the political corruption trial of Maryland Gov. Marvin Mandel extended its deliberations into the early evening hours today before breaking, giving rise to speculation that it was making a serious effort to resolve the issues dividing it and reach a verdict.

Attorneys and courtroom observers said that the fact the jurors met so late was a strong indication that they are heeding the judge's order that they rethink their positions, which have deadlocked the jury.

Wednesday morning U.S. District Court Judge Robert L. Taylor, the presiding judge, read a note from the jury saying it was unable to reach a unanimous verdict in the case. That raised the specter of a hung jury in a case that has generated considerable controversy and consumed large amounts of time and money, and the judge sent the jury back with instructions to try again.

The jury broke early Wednesday after a woman juror complained of illness.

Federal prosecutors officially asked Judge Taylor tonight to intervene in the deliberations of the jury if the two day deadlock over a verdict persists.

Admittedly "frustrated and disappointed," Assistant U.S. Attorney Barnet D. Skolnik said he filed the memorandum of three suggestions for breaking a deadlock because "it seemed like an appropriate thing to do."

The prosecutors suggested in their memorandum that Judge Taylor give a stronger request to the jurors to reach a verdict reread to the jurors laws covering the basic charge that the governor participated in a corrupt scheme, and ask the jurors to specify the focus of their dispute so the judge can decide if they need other legal guidelines.

While Skolnik described his memorandum as a simple statement that "here are some things to think about," the defense attorneys uniformly disapproved of the suggestions saying "it's an effort to maximize chances for conviction." in the words of attorney Michael Marr.

This afternoon, before the filing, Judge Taylor said he would leave the jury alone and let them deliberate over the weekend without "initiating further communication."

"I don't talk to this jury and I don't let them talk to me except in court," Taylor said. "There is no other option but to wait. So far as I know I'm not going to call them back (for another request to reach a verdict)."

In a rare open press conference, Skolnik talked for more than an hour about his previously private frustrations. "I'm disappointed . . . we would all like a verdict," he admitted.

"It's frustrating and difficult to cope with. I'm worried we may have a hung jury," he said.

Standing in the courthouse foyer surrounded by reporters, Skolnik dismissed several media reports about jury voting patterns. "The security is the most human beings can do," he said.

Skolnik also gave a personal history of the Marvin Mandel political corruption case itself, starting with the investigation of the six codefendants through the 1975 indictment, the mistrial and now the deadlocked jury."

"We got the first information regarding possible criminal violations by Mandel in June or July of 1975, (although) I've been hearing (unfounded) stuff about the governor for years. That's the kind of stuff someone in my position just hears about," he said.

He said today'e memo to the judge is part of the prosecutors' effort to "study all legitimate means of inquiring about what's going on in the jury room."

The memorandum reminded the judge that "there can be no doubt whatever . . . that it is rpofoundly in the public interest for there to be a resolution in this case."

The first suggestion was that the judge call the jurors back and read them a strong instruction that the jurors in the minority listen to those in the majority.

The second went to the core of what the jurors said was causing them the most problems. They could not reach a unanimous decision on the existence of a corrupt scheme, therefore they could not reach a verdict on any of the defendants. The prosecutors asked the judge to reread to the jury the laws covering the determination of a scheme.

There were some signs that the jury was digging in for a final solution. They asked for and received a blackboard and 12 notepads.