The District economy is plagued by a continuing exodus of business to the suburbs, resulting in a serious loss of blue collar and unskilled jobs, an advisory committee reported to the Barry administration yesterday.

The proportion of the city's professional, technical and managerial jobs -- positions held predominately by non-District residents -- rose from 35 percent in 1970 to 40 percent in 1978, but the D.C. economic growth rate has fallen to less than one percent, the committee said in a report.

Further, the District's gross economic product has been increasing at a rate of 0.2 percent a year since 1968, while the suburbs' GNP has been growing at a 7 percent clip, the report said.

The report, prepared by a blue ribbon panel of the city's business, labor and government leaders, concludes that the trends will continue.

"An overview of the District economy projected to 1985 shows a continuing growth in white collar and professional employment with a corresponding decrease in blue collar jobs," the report said.

"The trend in retailing and wholesale trade is toward further dispersion to the suburbs along with manufacturing," the report said.

"These combined trends indicate that a high rate of structural unemployment will persist in the District, while the suburbs may encounter manpower shortages in manufacturing, retailing and service occupations."

The report, which is to serve as a blueprint for the District government, was prepared by the Mayor's Overall Economic Development Advisory Committee. The chairman of the committe is Daniel Callahan, president of Riggs National Bank.

The report, which will be presented to the committee for final adoption later this spring, is supposed to lay out a course of action in developing an economic base in the District.

Included in the report are a variety of District government projects -- some of them already funded -- that are designed to lure industries, tourists and, ultimately jobs to the District.

The committee, however, in trying to stimulate public discussion of the report, held an open hearing yesterday. No members of the general public attended.

A spokesman for the committee jokingly called the empty hearing room "an implicit mandate from the people."

Nevertheless, the report is considered important to the city's business community and -- in an indirect, if just as important, way -- to the city population which bears the burden of the District's economic difficulties.

Not only does the business exodus mean that the city's poor have to struggle to find and get to jobs in the suburbs, it also means that the city's already troubled budget will be strained further by the burden on the city's government resulting from the need for social services.

The unemployment rate in the District is twice the figure in the suburbs, with little hope for change, the report stated.

"Those District residents who remain in the unskilled and semiskilled occupations are facing increasing difficulty in paying for housing, food, clothes and transportation" in light of the rising cost of living in the District, the report said.

"This has thrown an additional burden on the District government as the demand for direct and indirect subsidies and transfer payments increased," the report said.

If there is room for optimism, it is in the dramatic growth in the District of associations, law and accounting firms and major corporations, the committee said.