Mayor Marion Barry reached into the District government bureaucracy yesterday to fill six high-level jobs in his administration, including the long-vacant post of deputy mayor for finance.

The selection of the mostly little-known officials was seen as the first assertion of power by new City Administrator Carol B. Thompson, who played a strong hand in the mayor's choices, according to aides to Barry.

Thompson, a former deputy mayor for economic development, became city administrator this month after Barry reorganized the top levels of his government to have virtually all city officials, including two deputy mayors named yesterday, report to Thompson.

Aides to the mayor agreed that the officials would work for Thompson rather than create the competing power centers that undermined former city administrator Thomas M. Downs. "There are no political types," one Barry aide said. "{Thompson} has put herself lock, stock and barrel into the city administrator's post and nobody is going to challenge her."

Barry tapped Wylie L. Williams Jr., deputy director of public works since May, to become deputy mayor for economic development. Williams, a former city manager in North Carolina and Michigan, was an official of the International City Management Association in Washington from 1984 to 1987.

The mayor named longtime city official Robert Pohlman, now acting director of the Department of Housing and Community Development, as the new deputy mayor for finance.

Barry said Pohlman, who has headed the housing agency for 10 months and has worked closely with Thompson, would continue to run that agency until a new director can be found.

The deputy mayor for finance post has been vacant since the forced resignation of Alphonse G. Hill in March 1986. The cluster of agencies under the deputy mayor -- including budget, treasurer, controller and financial information services -- has suffered from numerous bouts of infighting, according to some aides. Barry twice last year named interim finance advisers to oversee the agencies and to stem the organizational problems.

Barry yesterday also named Sophia L. Green, a city government tax and bond adviser, as treasurer. The mayor nominated Raymond A. Skinner, acting director of the Office of Business and Economic Development, and Harold L. Thomas, acting director of finance and revenue, to assume those positions permanently.

Barry appointed Robert E. Petteway, a finance official who has overseen the city's checking accounts, as the new controller of the mayor's office accounts.

All of the officials except Petteway will be members of the mayor's Cabinet; Skinner and Thomas are subject to confirmation by the D.C. Council. City officials said it was uncertain whether the treasurer's post, which has been vacant many years, would require confirmation. The deputy mayor jobs and Petteway's controller position do not.

D.C. Council member Charlene Drew Jarvis (D-Ward 4), chairman of the Housing and Economic Development Committee, complained yesterday that Barry's deputy mayors do not require council review although dozens of officials under them do. The deputy mayor positions were created by Barry's executive order five years ago and, unlike agency heads, are not statutory positions subject to council review.

She also said Barry failed to consult with her or inform her of his decisions, which would have been the courteous and "politically smart thing to do."

Barry, who announced his latest staff changes after a Cabinet meeting at the Martin Luther King Jr. Library in downtown Washington, said he had looked both inside and outside his government to fill the positions, adding that he is proud that "the final six all come from within the ranks" of the city government.

Barry has acknowledged difficulty in filling vacancies created when officials left his administration at the start of his third term in office. He said his search for talent outside the District is hampered by the city's low pay scales for top executives.

Other city officials and aides to the mayor have said that Barry's recruiting also has been hurt by continuing federal investigations of his administration and what they described as unflattering publicity about Barry. Some professional public employees also say it is difficult for outsiders to join an administration in place for nearly 10 years.

Under the city's charter, no official may earn more than the mayor's annual salary, now set at $83,010. The city administrator earns $77,000 and most Cabinet-level officials have had their salaries capped at $70,000.

Barry last year appointed a committee that recommended sharply higher salaries for Barry's executives, but the mayor has not yet submitted its recommendations either to the council or to Congress for the necessary charter changes.

In his news conference yesterday, the mayor complained that some officials are reluctant to come under the "immense public scrutiny of the media" and said private employment "has less headache . . . less heartache."

Questioned about the long-term vacancies, the mayor said, "There are some members of the media who want to rush me . . . to stampede me." He said he would rather be "slow and sure."

Although Barry now has filled most positions in his government, he still has not found someone to be staff director for the mayor's office, a post that became vacant when Brenda Williams left in January.

Barry has had four staff directors in just over two years. Herbert O. Reid Sr., who also is Barry's legal counsel and a professor at Howard University, has been serving as interim staff director.

Reid said yesterday that Barry's latest appointees were required to submit five years of income tax records and other personal data for review by Reid before being named to their jobs.

A similar requirement was made for other officials at the start of Barry's term.