The number of jobs in metropolitan Washington is expected to have increased by more than 44 percent above the 1976 level by 1990, rising from 1.4 million to 2 million during that 15-year period, according to projections in a report by the D.C. Department of Employment Services.

At the same time, however, the District's share of jobs in the area is expected to diminish, from 42 percent in 1976 to 32 percent by 1990, the DES estimates in its 1985 annual planning report. In fact, by 1990, the District's share of jobs in the area will drop in every occupational group for which data are available, according to the DES.

The continuing decline projected for the District's share of area jobs reflects a national trend toward suburbanization of jobs and people in urban areas, DES officials said.

In the meantime, the number of households in metropolitan Washington is expected to increase at a faster rate than the population between 1980 and 2000. During that span, the number of households is expected to rise 30.9 percent, compared with an estimated 17.9 percent gain in total population in the area. As a result of increased households, the DES said, there will be greater demand for public utilities, housing, construction, appliances and other types of consumer goods and services by 2000.

Most of this demand will be in Washington's suburbs because jobs as well as population growth will continue to diminish in the District, DES projections indicate.

"In all likelihood, the relative number of jobs and people located in the District of Columbia will decline gradually through the remainder of the decade," officials note in the report.

The economic growth and vitality that has characterized the Washington Standard Metropolitan Statistical Area (SMSA) over the past 20 years "tends to run counter to the economic health of its central city," DES asserts in the annual planning report. Nonetheless, after three years of economic decline and stagnation, the District's economy made strong gains in 1984, said DES. There was, in fact, widespread improvement in the area's economy during 1984.

Assuming continued growth in the national and area economies, the short-term employment outlook appears to be positive for the District, officials concluded. The long-term outlook -- to 1990 -- is much less certain, however.

A DES official emphasized that the department's projections are based on trends. And even though the projections are "very conservative," he added, "we think we are still pretty good on the totals."

The one area in which the department might have underestimated job growth is the District's retail trade sector, the official acknowledged. Several retailers have made firmer plans for new stores and expansion of existing operations since labor market projections were made, he said.

A report that the DES issued earlier this year focused on changes expected to occur by 1990 in the industrial and occupational composition of the SMSA. The annual planning report is a more comprehensive document, an official explained.

The DES compiles labor market information for the District and other jurisdictions in the Washington SMSA. The SMSA includes the District; the Virginia cities of Alexandria, Fairfax, Falls Church, Manassas and Manassas Park; Fairfax, Arlington, Prince William and Loudoun counties in Virginia, and Montgomery, Prince George's and Charles counties in Maryland.

The annual planning report, which was prepared by the DES' division of labor market information, research and analysis, contains a current profile of the area's labor market as well as industrial and occupational projections out to 1990.

Those projections show that the services sector in the District -- the only one to register gains in employment between 1979 and 1983 -- will continue to expand throughout the current decade. The continued "exuberant performance" of the services industry in the District will produce 212,700 jobs by 1990, a gain of 9,400 over 10 years.

The growth in services in the local economy "parallels the evolutionary shift" in the national economy from an industrial to a services economy, officials said.

Indeed, in Washington's suburbs, the services industry has maintained, for more than a decade, the best performance record of any local industry in terms of employment growth, the planning report points out. And projections show this sector will post significant employment gains through 1990. By then, the number of jobs is projected to increase by 144,700, or 49.2 percent, over the 1983 total.

Government jobs, on the other hand, are expected to increase at a much lower rate in the suburbs. Federal jobs in suburban jurisdictions are projected to increase by only 12,500, or 8.8 percent, between 1983 and 1990. As many as 31,000 state and local jobs may be added by 1990.

Although government continues as the biggest industry in the District, the outlook through 1990 is one of "restrained and cautious expansion" of job opportunities in the federal government. The DES projects an increase of fewer than 6,000 federal jobs in the District between 1984 and 1990.

Federal budget cuts and reductions-in-force put in effect by the Reagan administration had a greater impact on the District's economy than they had in the suburbs, the DES recalled. Federal jobs in the District increased by 8,000 between 1976 and 1979, but decreased by 19,900 during the next four years. In the suburbs, meanwhile, federal jobs increased by 1,100 between 1976 and 1979, and expanded by 8,000 between 1979 and 1983.

Only a marginal increase, supported mainly by a rise in commercial building, is expected for the remainder of the decade in the construction industry in the District. Based on projections for the 1983-1990 period, employment will increase less than 2 percent.

The employment outlook in the construction industry is vastly different in Washington's suburbs, however. "As long as the economic outlook for the nation remains positive and interest rates and mortgage rates remain favorable, rising demand for housing and other types of construction is expected to stimulate new construction activity" in suburban areas, say District economists who prepared the planning report. Based on those assumptions, the number of suburban jobs in the construction industry is expected to increase by 13,200 from the 1983 total of 64,600.

Wholesale and retail trade, the third-largest sector in Washington's suburbs, is expected to get a bigger boost from the growth in population and higher personal income. Hence, retail trade jobs are expected to increase by 84,300 between 1983 and 1990.

Economic recovery is not expected to be strong enough to stop a long decline in this sector in the District, however. Employment in the District's wholesale trade is expected to decline by 19 percent by the end of the decade, while only a marginal drop of 2 percent is projected for the retail sector.

Employment in the finance, insurance and real estate (FIRE) group should benefit from increased consumer spending, contributing to a 7.1 percent increase in that sector's jobs in the District, according to the planning report. At the same time, employment in this industry is expected to increase moderately in the suburbs, from 60,000 in 1983 to 68,400 in 1990.

Officials caution that none of the projections for the FIRE segment allow for employment changes that could result from regional interstate bank mergers. Mergers among banks in the area could lead to elimination of duplicate operations and jobs. On the other hand, some mergers may result in expansion of services and staffs.

One of the brighter spots for the District is a projection of 9 percent growth in employment in the transportation, communications and public utilities sector. Employment in this sector increased by 6.2 percent between 1979 and 1983. Strong growth in this grouping also is projected for suburban communities, which are likely to gain more than 18,000 jobs.

With a services-oriented economy, the Washington area historically has had little manufacturing. Growth in this sector is expected to increase 20 percent in the District between 1984 and 1990, nevertheless.

Led by growth in the printing and publishing industries, manufacturing may post a gain of nearly 3,000 jobs by the end of this decade. The number of manufacturing jobs in the suburbs is expected to increase by 8,000, but the industry's share of suburban jobs should remain below 5 percent through 1990, according to DES.