Suspended Maryland Gov. Marvin Mandel has become an influential, behind-the-scenes figure in the Democratic gubernatorial campaign, maintaining almost daily telephone contact with top aides of several candidates and venturing now and then from his secluded Anne Arundel County home to act as a go-between for contesting factions in the Sept. 12 primary.

Mandel, who controlled state Democratic politics for nearly a decade before his conviction on corruption charges last August, is regarded by some candidates and advisers as an elder statesman whose political knowledge and negotiating abilities are still invaluable, despite his legal troubles.

Over the last three months, Mandel has been in frequent contact with aides to candidates Blair Lee III, Francis (Bill) Burch and Steny H. Hoyer, who dropped his gubernatorial campaign in early June to run as Acting Governor Lee's lieutenant governor candidate.

Mandel played an early role in the negotaitions that led up to the Lee Hoyer alliance, meeting twice in early May at the Sheraton-Lanham with Lee adviser Maurice R. Wyatt, Hoyer and Hoyer's close associate, attorney Peter F. O'Malley. The purpose of those meetings, according to the participants, was to see whether Hoyer would be interested in dropping back to the lieutenant governor or attorney general slot on someone else's ticket.

In addition, according to O'Malley, the suspended governor called him once in late May to see whether Hoyer still was considering running on the ticket headed by state attorney general Burch. O'Malley said the call came the day before Hoyer joined Lee's ticket.

Although O'Malley said Mandel was "calling on behalf of Burch," the attorney general said yesterday that he had "no recollection' of ever asking Mandel to make such a call and Mandel said he did not remember placing it.

Hoyer said his friend O'Malley informed him of the call the next day.

"Perhaps the message wasn't all that clear," said Hoyer. "As a matter of fact, Pete told me he wasn't really sure what the message was. But he did say that Marvin called him on behalf of Burch."

O'Malley said in an interview yesterday that he had met privately or talked by telephone with Mandel on several earlier occasions to discuss Hoyer's gubernatorial campaign. He said he never was concerned about the political ramifications of these discussions.

"I think Marvin Mandel is the best informed and most knowledgable political person in the state," said O'Malley "He knows the most about state government and his knowledge of politics in Baltimore is head and shoulders above anyone else's."

O Malley recalled that on March 28, more than a month before Mandel was brought in for the early Lee-Hoyer negotiations, he met with the suspended governor and Wyatt at the Sheraton-Lanham "to impress upon them that Steny was a strong candidate."

Hoyer said yesterday he was aware that O'Malley was "talking once in a while with Marvin," and that he saw nothing wrong or unusual about it.

"I think that every major candidate has had communications with the former governor," said Hoyer. "He is perceived as having moxie and intellectual savvy and his opinions tend to be parroted by others. Not that anyone feels that he should be part of their team. The guy just serves the functions of a communications center. He's talking to everyone all the time and knows what's going on."

Mandel, in an interview two weeks ago, said that he spends much of his time on the telephone with politicians. "(Political leaders) will call me or I would talk to them and they would tell me what they're doing, where they're going, and we discuss different phases of campaigns, how people are doing, what's developing."

Mandel said he was not taking sides in any of the contests. "I have not attempted to pull together any statewide group for anyone," he said. "I have contact with them all the time, but mostly it's because we like to talk politics. It never gets out of your system."

The political strategists Mandel frequently confers with include O'Malley, Wyatt and Philip Z. Atfeld, Burch's campaign manager. Wyatt, the former patronage secretary for both Mandel and Lee, maintains almost daily contact with Mandel. Altfeld said that Mandel calls him about once a week. He said Mandel's opening question is always the same: "What's happening?"

Since his conviction last August, Mandel, 58, has served as a business consultant, helping small businessmen deal with government regulations. He works from his home in Arnold, in Anne Arundel County, with his wife, Jeanne. The appeal of his conviction will be heard next week by the Fourth Circuit Court of Appeals in Richmond. If the court upholds the conviction, Mandel faces a four-year prison sentence.

In recent months, Mandel has made frequent appearances at political fund-raisers at the personal invitation of the hosts. He is treated as a dignitary at the affairs, always drawing more attention than the candidates. At Lee's fund-raiser at the Baltimore Civic Center in April, Mandel attracted such a large crowd of well-wishers that it appeared he was the guest of honor.