Job growth in the Washington area outpaced the national rate between 1980 and 1985, according to new figures that underscore the continuing transformation of the region's once-rural suburbs into urban centers of office complexes, shopping malls and traffic jams.

The region gained 172,700 jobs during that period, an increase of 10 percent, with more than half the gain taking place in Montgomery and Fairfax counties, according to the preliminary results of a Metropolitan Washington Council of Governments survey.

Nationwide, the number of jobs increased by 8 percent over those five years, according to the Bureau of Labor Statistics.

In the Washington area, the type and location of the new jobs reflects "the continuing shift of the region's economy from a government town to a financial and services center," Jay Langford, COG's chief of planning and analysis, wrote in an article discussing the first results of the survey.

The new financial jobs include those in banks, thrift institutions, credit agencies, insurance, real estate and investment services.

The new service jobs run the gamut from designing the Strategic Defense Initiative, or "Star Wars," to providing janitorial services to millions of square feet in new office space.

The District of Columbia continued to lead other area jurisdictions in the total number of jobs, with 686,000, more than a third of the region's almost 2 million jobs in 1985, COG's figures show.

But that was only a 3 percent increase over the five-year period and was the second-lowest rate for any jurisdiction, "despite construction of millions of square feet in office space," Langford said. However, those 20,100 new jobs exceeded the number created in several counties and cities with higher growth rates.

Not surprisingly, the most jobs were added in the two counties that have seen the highest population growth, according to recent U.S. Census Bureau estimates. Montgomery County added 49,000 jobs, an increase of 16.2 percent, while Fairfax County added 39,000, up 18.1 percent, the COG found.

In both of these counties, job growth was centered in areas identified by planning experts as "emerging cities," or new urban areas that offer more jobs than homes, such as Tysons and Rockville/Gaithersburg.

The City of Rockville saw a 20 percent increase in jobs over the five-year period, making it the second-fastest growing jurisdiction in the COG's figures.

The highest rate of job growth was found in Leesburg and Loudoun County, immediately west of Fairfax County. Most of the growth in Loudoun has been in the county's eastern end, where new electronics and other high-technology firms have clustered around Dulles International Airport.

Loudoun added 6,100 jobs, a small number compared with the inner counties, but a 35 percent increase for a jurisdiction that is still mostly farmland and increasingly the target of land speculation.

"The growth will continue; if anything it will increase, primarily in the high-tech area," said Pamela Wev, the county's director of economic development.

The decline in agricultural jobs in Loudoun has been more than offset by the employment growth created by companies involved in the research, design, manufacture and shipping of electronics components and products, Wev said.

These companies are "almost entirely geared to Dulles for export or shipping" because their products tend to be small and light, compared with traditional manufactured goods, Wev said, noting the steady increase in the cargo traffic at Dulles.

The Loudoun-Fairfax county line bisects the airport and economic development on both sides is similar, reflecting "increasing linkage" between the two Northern Virginia counties and a similar pattern of economic growth throughout the suburbs, said Langford.

"The firms in Loudoun will be consulting for the space station in Reston," Langford said of the National Aeronautics and Space Administration's decision to build the project's office in Reston.

This move is expected to generate millions of dollars worth of contracts, while attracting more companies and more jobs to the area.

While "high technology" computer, aerospace and biotechnology firms represent some of the region's most glamorous job growth, they also have stimulated an enormous increase in the more mundane jobs needed to serve a growing population, planning experts said.

In Montgomery County, for example, most of the job growth took place along the I-270 corridor, known as "Biotech Valley" for the proliferation of genetic engineering and health services companies, and along Rockville Pike, which has seen strong retail and office growth, Langford said.

In Prince William County, many new jobs are related to Potomac Mills Mall, just off I-95. In 1985, retailers were the largest single source of jobs in the county; in 1980 the federal government held the title.

In Northern Virginia, secretaries are expected to represent the category of greatest job growth between 1980 and 1990, according to a Virginia Employment Commission forecast.

One trend reflected in the survey numbers is the growth of jobs along Metro routes.

In Montgomery County the jobs have appeared along the Red Line, toward Shady Grove and around Silver Spring.

In Arlington, the growth has taken place along the Blue and Orange lines around Rossyln and Ballston.

In Fairfax, most of the growth has clustered along major transportation corridors such as the Dulles Access Road, I-66 and the Shirley Highway.