Former Maryland governor Marvin Mandel lost his latest bid yesterday for reversal of his political corruption conviction. Now only the U.S. Supreme Court stands between him and a four-year prison term. o

By a tie vote, the full federal appeals court in Richmond refused to rehear the case of Mandel and five codefendants. That left their convictions standing on the basis of an earlier tie vote, which one dissenting judge called a "serious injustice."

Although federal prosecutors in Baltimore could seek imprisonment within weeks for Mandel and the others, Maryland U.S. Attorney Russell T. Baker aid he will not do so.

Yesterday, in his lawyer's Baltimore office, a pipe-puffing, sardonically smiling Mandel told reporters he won't give up even if the Supreme Court rules against him. "I don't intend, even after that court has stopped, I don't intend to stop until somehow, some way I can prove the fact that I am not quilty of doing anything to hurt or harm or embarrass the people of the state of Maryland," he said.

Yesterday's order from the 4th U.S. Circuit Court of Appeals set the stage for the final act in the four year legal saga that has carried Mandel through one mistrail, one conviction, one reversal, a dramatic 45 1/2-hour return to the governor's chair and then a reinstatement of the conviction last July.

Now, lawyers for Mandel and his codefendants must convince at least four of the nine Supreme Court justices that the case is worthy of the high court's review.

Mandel was convicted in August 1977 of 17 counts of mail fraud and one count for rackettering after prosecutors charged that he had accepted $350,000 in gifts, vacations and stock from wealthy friends in return for secretly using his office to enrich their business interests.

These friends -- Irvin Kovens, Harry W. Rodgers, William A. Rodgers, W. Dale Hess and their lawyer Ernest N. Cory -- were Mandel's codefendants.

The convictions of all six men had ended the second trail -- the first ended in a mistrail eight months earlier -- and made Mandel the first Maryland Governor to leave office in disgrace.

But last January, a three-judge panel of the appeals court overturned the convictions. Government prosecutors appealed to the full court. With six judges sitting, the full court reinstated the convictions by a 3-to-3 vote last July.

A tie vote has the effect of upholding the lower court, which in this case, was the federal district court in Baltimore where the men were tried.

It is that tie vote and the 4-to-4 deadlock by which the court denied Mandel's rehearing bid yesterday, that will be the heart of Mandel's appeal to the Supreme Court, according to his attorney, Arnold Weiner.

Judge Francis Murnaghan Jr., who joined the 4th Circuit after Mandel's conviction was reinstated, dissented from the court's decision yesterday, saying "that the court's failure to decide this case constitutes a serious injustice."

"This is no ordinary case," wrote Murnaghan, a powerful Baltimore lawyer recently appointed to the bench. "It's consequences on the entire political system of the state of Maryland are enormous. It cries out for a proper resolution, where such a resolution is possible," he wrote.

The judge offered to remove himself from hearing the case or participate in the appeal process in order to assure an uneven number of votes on the court.

Several legal experts were surprised by Murnaghan's unusual offer, particularly because he is so new to the court. "For the new guy on the block, it would have been easy for him to duck out," said on lawyer.

There now are nine judges on the 4th Circuit. One judge long ago removed himself from hearing the case because of his Baltimore connections. Of the eight remaining, Murnaghan noted that the court's newest judge, James A. Sprouse of West Virginia, might want to "recuse" -- or disqualify -- himeself from hearing the case.

"If he did not recuse himself, I would," Murnaghan wrote. "If he did recuse himself, I would sit."

Chief Judge Clement F. Haynsworth Jr. wrote a two-sentence order denying the rehearing request. Judge H. Emory Widener Jr., writing for himself and Judge Donald S. Russell, dissented, saying he could not overcome his reservations about sending criminal defendants to prison on a tie vote.

Mandel, seated next to his wife Jeanne and his attorney, Weiner, at the news conference, expressed his own disappointment at the vote: "The way we're losing without losing leaves too much unanswered."

Along with the question of what Weiner called the unconstitutionality of sending criminal defendants to jail on tie votes, the appeal to the Supreme Court also will focus on issues already raised in the long legal tug-of-war.

The defense has contended that Judge Robert L. Taylor, who presided at Mandel's 1977 trail, allowed the prosecution to use improperly "hearsay" testimony by several state senators to prove that Mandel wanted his veto overridden on a piece of race track legislation.

The race track deal was a key to the prosecution's case.

When the rundown Marlboro Race Course in Prince George's County was owned by some Western Maryland businessmen, Mandel vetoed a bill that would have doubled the number of lucrative racing days allocated to the track.

After the veto, Hess, the Rodgers brothers and Kovens secretly purchased the track at a price drastically reduced because of the governor's action.

In 1973, the next legislative session when lawmakers routinely consider overriding vetoes, the prosecution charged, Mandel quietly worked to have his own veto overridden. The track suddenly took on increased value.

The defense argued that the judge had improperly allowed state senators to testify about the alleged override maneuver by citing comments made on the Senate floor. The senators said they inferred that Mandel wanted his veto overriden.

The defense, in its previous appeals, also argued that Judge Taylor allowed the jury to consider other improper evidence and failed to instruct the jurors on the relevant law in the case before they retired to deliberate.

It was on these issues and the hearsay question that the appellate panel last January based its reversal of the convictions.

The Supreme Court appeal also will likely include one other major issue: a defense contention that the prosecution overextended the federal mail fraud law to win the Mandel conviction.

But legal sources familiar with the government's position have stated that several other appellate courts around the country have decided that issue in favor of the government, and it is unlikely the Supreme Court would agree to consider it.

The trail and appeals process already have cost the defendants more than$1 million in legal fees, according to several sources.

Mandel noted yesterday that the case "sometime ago . . . drained all there is to drain" financially.

But he said there is no question he would continue his appeals. "If you don't appeal . . . you leave the impression . . . that you may have done what was alleged to have been done."

One of Mandel's codefendants, Hess, hearing the news at his Florida vacation home, took the news stoically.

"There's nothing I can do about it," said Hess. "They (the appeals court) have the final say in this round, but there'll be others. We will ask the Supreme Court to hear it."

Hess, who retained his back-slapping, hail-fellow demeanor through most of two trails and now three appeals, said he "couldn't be better." He said he and his wife, Dorothy, went to Key Largo on Sunday to play in the Ocean Reef Club homeowners' golf tournament this week.

"The sun is shining and I just finished a wonderful round of golf," he said in a telephone interview. Asked about his score, Hess said, "I don't want to say, or someone will challenge my handicap."