Manuel Deese, a former Alexandria city administrator, was sworn in yesterday as city manager of Richmond, thus becoming the first black city manager of a major Southern city and one of a handful of top black municipal officials in the South.

The appointment of Deese, 37, had been approved Monday night by a unanimous vote of the nine-member Richmond City Council and was hailed yesterday as a major step toward better race relations by black and white leaders of the former capital of the Confederacy.

"Richmond's come a long way," said Councilman Wayland W. Rennie. "I'm thrilled, said Claudette B. McDaniel, one of five blacks on the council. "I think he (Deese) is going to be able to deal with both the business and the grass-roots communnity."

Deese, a former assistant to the city manager of Alexandria, has been acting city manager of Richmond since September, when the black council majority fired William J. Leidinger in an episode that split the city racially and led to bitter recriminations between black and white politicians.

Leidinger, who is white, was accused of the black majority on council of paying too much attention to the city's financial community and of being insensitive to the needs of Richmond's large black population.

Deese pledged yesterday to work with all council members regardless of race. "Since I've been acting city manager, I've been able to bridge the gap," he said.

Reaction yesterday tended to support that view. Rennie, who was not a member of the 11-person selection committee that nominated Deese from among 85 applicants, said he had supported Deese all along. "I was on the outside looking in -- and cheering," he said.

"He has been under the consideration of this committee for a long time, and in my opinion, he should have been," said James Wheat Jr., head of Wheat First Securities, a leading Richmond investment firm.

Deese worked in Alexandria from 1971 to 1974, when he became one of Richmond's three assistant city managers, and was appointed second in command by Leidinger in 1977.

Alexandria budget director James Randall, said Deese "sensitive to different perspectives. He could deal equally well with the liberal and conservative elements."

Deese, who grew up in Pittsburgh and holds degrees from Morgan State and American universities, is a softspoken administrator who shunned publicity during the Leidinger controversy.

"He's very easy to work with," said Randall. "I would suspect he's very easy to work for."

Deese, who worked for the National League of Cities before moving to Alexandria, said he decided to try for the city manager's job in Richmond shortly before the fall deadline for applications. "The potential for the future development and growth of Richmond is here," he said. "What I have to do is insure that the administration and the management of the city continue to serve the people."

Symbolic of the political peace Deese's appointment might have brought to Richmond is the council vote on his nomination, one of the few unanimous votes the council fembers have cast on a major issue since the Leidinger controversy last summer.

That vote made Deese one of the South's few top black municipal bureaucrats. Atlanta has a black chief administrative officer and several lesser cities have black city managers, but Richmond is the first major city in the South to hire a black city manager, according to the International City Management Association.

"I serve as a role model for disadvantaged kids and minority groups to see that they can succeed if they try," Deese said. "My vote was 9 to 0."