Attorney General Stephen H. Sachs is waging an intensive campaign to persuade Rep. Parren Mitchell, the longtime civil rights activist and dean of Maryland's black elected officials, to serve as Sachs' running mate in his uphill battle to become governor of Maryland.

Several well-placed sources close to Mitchell and to the Sachs campaign said that Mitchell, 63, who announced his retirement from Congress last October, is on the verge of agreeing to run for lieutenant governor on a ticket with Sachs. If the duo is successful, the post would make him the first black ever elected statewide in Maryland.

"Parren is three-quarters of the way through the negotiations," a source close to Mitchell said yesterday. "We do not see a hitch."

Mitchell declined to comment on the speculation but said he would hold a press conference next week.

Sach's campaign manager, Blair Lee IV, would say only that "there is a selection process going on right now; there's a list of four names and Parren Mitchell's is certainly on it."

Nevertheless, Lee added, "Steve and Parren have had a longstanding and mutual respect. They are sympathetic in outlook, in their view of government and what government is for -- which is for people." Sachs could not be reached.

If Mitchell does accept the job, the decision could prove a major boost to Sach's struggling bid for the Democratic nomination against Baltimore Mayor William Donald Schaefer, who has already raised more than a million dollars for his campaign and has led Sachs in the polls for months.

Mitchell, the only black ever elected U.S. representative from Maryland, would likely bring the Sachs campaign the benefits of his tremendous popularity in Baltimore's black community, an important voting bloc that has strongly supported Schaefer.

A senior member of the Mitchell family, which has received national attention for its long record of civil rights activism both locally and nationally, he has enjoyed both broad name recognition and popular support since his election in 1970. His seat was considered one of the most secure in the House of Representatives in recent years, and he is the senior member of the state's House delegation.

Locally, he has been a frequent critic of the Schaefer administration's efforts on behalf of the poor, and in recent years he has repeatedly used his public appearances to call attention to the contrast between what he calls "the two Baltimores" -- the glittering world of the Inner Harbor and fast-rising office development on the one hand, and neighborhoods still suffering from an array of social problems like crime, drug use and teen-age pregnancy on the other.

In part because of his longevity and record of advocacy, Mitchell's announcement of his plans to retire brought dismay in some political quarters.

An influential group of black ministers called upon Mitchell to reconsider his decision to retire, and tangible evidence of Mitchell's standing in the community appeared in the form of red and white signs planted in front of house after house in West Baltimore. They said, "Run, Parren, Run."

But Mitchell recently said he would remain firm in his decision to leave the House.

One potential drawback of Mitchell as Sachs' running mate could be that the campaign would have to answer Mitchell's earlier statements that he was retiring in part because he was fatigued and needed rest. He told reporters that he hoped to remain active in the community in some way.

Lee refused to say who the other contenders are.

In political circles, however, Maryland Secretary of State Lorraine Sheehan, a strong Sachs supporter and former state delegate from Prince George's County who is now the state's highest-ranking woman official, has made no secret of her desire to be considered for the post, nor has former Maryland State Teachers' Association president Janice Piccinni. Neither Mitchell nor Piccinni could be reached last night, but Sheehan said that if Mitchell is Sach's choice she will strongly support the decision.

"Parren Mitchell is certainly a senior statesman of Maryland. He knows Maryland well. I think this wins the election for Steve Sachs," she said.