Albert P. Russo, apparently unhappy at not being named permanent director of the D.C. Department of Human Services, will resign Friday as acting director of the agency, it was announced yesterday.

Russo's departure leaves Mayor Marion Barry with the task of filling the top post in the city's largest and most troubled department. The Barry administration has sought to bring the agency -- formerly the Department of Human Resources -- under control for more than a year.

Sources said that Russo, 60, who had the title of director of the old Human Resources Department, was unhappy at being named only acting director of DHS when its reorganization went into effect last week.

Russo denied last night he was disgruntled at not being named as permanent DHS director. He said he wanted to take advantage of early retirement benefits.

But City Administrator Elijah B. Rogers said, "Al told me that if he had his druthers, he would have been named director outright." Russo has told another source that he was not interested in staying on at DHS unless he received the permanent position.

Russo took over leadership of the department in 1976, after then-mayor Walter E. Washington removed Joseph P. Yeldell as director. Yeldell had been accused in published reports and congressional audits of mismanagement of the agency and conflict of interest.

Barry has promised repeatedly to improve DHS services. During his mayoral campaign in 1978, he talked of splitting the agency into separate health and social services departments. But he later rejected the idea in favor of internal reorganization after a task force concluded that the agency's main problem was mismanagement.

In an interview during the campaign, Barry said he wanted to keep Russo in District government but "not necessarily" as head of the massive agency.

Most City Hall observers attribute Russo's relatively long tenure under Barry as a holdover from the Washington administration to Russo's close working relationship with City Council member Polly Shackleton (D-Ward 3). Shackleton is an ally of the mayor and heads the council committee that oversees DHS.

Yeldell was a flamboyant, high-profile administrator and a political intimate of former mayor Washington. The gray-haired, pipe-smoking Russo, by contrast, has seemed uninterested in the intricacies of District politics, preferring to quietly work long hours and to make himself far more available to the press than his predecessor.

Nevertheless, the agency has come under the same kinds of criticism for failure to deliver adequate care and for lax management of welfare payments under Russo's direction as it suffered in the past.

After a fire in an agency approved foster care home at 1715 Lamont St. NW last year that killed nine persons, Barry publicly repremanded Russo for not enforcing laws regulating halfway houses and nursing homes.

Rogers said yesterday the search for a permanent DHS director would focus on candidates who can "get a lot of work out of people."

"We think the major problems over there are the need for strong management and getting more productivity out of the staff," Rogers said. "For too long people over there were allowed to pass the buck.

"We went to look at the whole relationship with the private sector and what its role ought to be in providing human services," Rogers said, adding that the Barry administration wants a director who is "sensitive to the needs of low-income residents."

Barry announced that William Whitehurst, currently Russo's deputy, will replace Russo as acting director until a permanent successor is found.

Whitehurst has held a variety of posts within the agency since he joined it in 1970. He holds a master's in clinical psychology.

The mayor praised Russo for giving "exceptional, tireless and dedicated service to the people of the District." Rogers added that Russo "gave his all to the department."